Member Defections: Automatic By-elections

Roz Savage Excerpts

Monday 16th March 2026 Westminster Hall

[Dr Roz Savage (South Cotswolds) (LD)]

I beg to move,

That this House has considered e-petition 737660 relating to automatic by-elections following Member defections.

It is a pleasure to serve with you in the Chair, Sir Roger. I thank those who have shown up for this debate; we may not have a large quantity here, but I am sure that we will have quality. My role this afternoon is primarily to introduce the debate on this petition on behalf of the Petitions Committee, outline some of the arguments that have been raised and give colleagues an opportunity to consider the issue.

Let me start by thanking the many thousands of people who signed this petition, which was started by Barry McIlhinney from Perth in Kinross-shire. It gathered more than 129,000 signatures, including 252 of my South Cotswolds constituents. It may not surprise anybody to hear that the four constituencies with the highest number of signatories were Fareham and Waterlooville, Newark, Romford and East Wiltshire—I shall leave it to hon. Members to spot the pattern.

Whatever view Members may take on the proposal, it is clear that the petition touches on what some commentators have called a crisis of confidence in our democracy: the suspicion—we can debate whether it is a fair one—that some MPs are here less to represent the interests of their constituents, and more to represent their own. The petition reflects a wider public interest in the relationship between voters and those who represent them, and in how that relationship operates in the intervals between general elections. The key question is, when voters decide who to vote for, what exactly are they choosing? Some argue that voters elect an individual, full stop, and that what matters most is the person whose name appears on the ballot paper. However, others suggest that party affiliation is a significant part of how voters make their decision, as they view a candidate’s political party as shorthand for a particular set of values and attitudes.

I would suggest that in the real world, for many voters, the decision that they make in the privacy of the polling booth at a general election is a complicated calculation: an algorithm involving party values, historical loyalties, headline policies, party leaders, local reputations and individual personalities. In our first-past-the-post system, that also increasingly includes tactical voting, as in many cases voters feel that they must choose not simply the candidate that they most admire, but the one most likely to defeat the candidate that they most fear. That is one of the quirks—some may even say flaws—of our electoral system. MPs may like to think that every vote that they win is the result of their particular blend of wit, charm and intelligence, but I suspect that, if elections were decided purely on our unique personalities, many of us might not be in this Chamber at all.

My point is that voters often consider a range of factors when deciding how to cast their vote. This petition invites us to consider what should happen if one such factor—political party affiliation—changes during the course of a Parliament. Political parties clearly play a very real role in getting their candidates elected, investing time, money, wisdom and infrastructure. Parties pay the deposits and give their candidates training, campaign support and access to networks of volunteers. It could be argued that an exceptionally cynical candidate could simply align themselves with the party that had the most successful campaigning machine, and then promptly jump ship once they arrive here—I am not for a moment suggesting that anybody would do such a thing.

During a general election campaign, the people knocking on doors, delivering leaflets early in the morning, getting out the vote late in the evening and standing outside polling stations in the rain are often long-standing party members, supporting the person they see as their party’s candidate. Many would argue that party affiliation forms an important part of the democratic bargain made with voters at a general election. However, at the same time, others emphasise that MPs are elected as representatives rather than as delegates, and that they must retain the freedom to exercise their judgment and follow their conscience once elected.

This petition therefore invites us to consider where the balance should lie between those two contrasting principles. The question is whether the current constitutional arrangements strike the correct balance, or whether there should be some additional form of democratic mechanism when an MP decides to move to another party.

Some argue that a by-election would allow voters to confirm whether they still support their MP after a change in party affiliation. They also argue that, if the defecting MP is sufficiently confident in their wit, charm and intelligence and that they hold a special place in the hearts of their constituents, they should not be afraid to return to the polls.

[Robbie Moore (Keighley and Ilkley) (Con)]

All political parties undertake a vast amount of data collection on their voter base. A good proportion of that data illustrates that the vast majority of people will cast their vote based on the political party rather than the individual. The individual carries less weight in someone’s mind when they cast their vote. Therefore, does the hon. Member agree that triggering a by-election on the basis of a defection is crucial to ensure that voters are represented by someone who reflects how the vast majority cast their vote at the ballot box?

[Dr Savage]

The hon. Gentleman makes an excellent and valid point. My main job today, on behalf of the Petitions Committee, is to present both sides of the argument, but the point about data on voting intentions, which we work so hard to glean on doorsteps, is a key factor in the debate.

Others raise concerns that a requirement for a by-election could have unintended consequences, including potentially strengthening the power of party leaderships or discouraging MPs from following their conscience due to legitimate dissent. At this point, I want to clarify that when talking about defections, I am not talking about the case where an MP loses the Whip for reasons to do with the leadership, but about voluntary defections undertaken by an MP themselves. I do not think any of us would want a world where party Whips could threaten an MP with a mandatory by-election if we displease them in some way.

Public opinion on this question appears to be mixed, although polling suggests it is an issue on which many people hold strong views. Some surveys indicate that around 40% of respondents believe that it is unacceptable for an MP to defect, while others suggest that a majority of voters think a defection should trigger some sort of electoral test. Those numbers do not resolve the constitutional question, but they suggest that people far outside Westminster really care about this matter.

It is also worth putting the question into perspective. Party defections in this country are relatively rare, although they obviously sometimes occur in clusters during periods of political turbulence—possibly such as we are going through now. The last MPs to resign their seats and seek fresh mandate after defecting were Douglas Carswell and Mark Reckless in 2014, when they left the Conservative party to join UKIP. They refought their seats in by-elections.

[John Lamont (Berwickshire, Roxburgh and Selkirk) (Con)]

The hon. Lady is making the case well on behalf of the Petitions Committee. Over the years, there have been a number of examples of some of my former Conservative colleagues ending up alongside Lib Dems in the House of Commons. In those circumstances, is the hon. Lady of the view that there should have been a by-election for those MPs to get their mandates restated?

[Dr Savage]

I thank the hon. Gentleman for making that point. What we are talking about is the principle of the matter rather than specific defections from any one party to another.

This constitutional question has also been considered by Parliament previously. In 2011, a private Member’s Bill proposed that MPs who changed their party affiliation would have to face a by-election, and in 2020, another Bill proposed extending the Recall of MPs Act 2015 so that a voluntary change of party could trigger a recall petition. Neither progressed through Parliament, but the fact that the issue has arisen more than once suggests that it raises enduring questions about representation and accountability.

I would like to share some perspectives from other countries, because this is not a uniquely British debate, and other democracies have taken different approaches. Some, such as India, have adopted strict anti-defection laws under which MPs can lose their seat if they leave the party on whose ticket they were elected. Indian MPs are also, for the most part, compelled to vote with the Whip, which must make votes very, very boring. Others, such as New Zealand, have legislation designed to discourage what is sometimes referred to as “waka jumping”—I am reliably informed that that is effectively jumping from one canoe to another, which I can say from personal experience sounds like a very bad idea—although that approach has also prompted debate about the balance of power between MPs and party leadership. South Africa experimented with allowing MPs to cross the Floor, but later decided that that was a poor idea and prohibited it. That shows that views can change about how best to preserve electoral legitimacy.

The UK system has its own traditions and constitutional principles. Party affiliation plays an important role in how Governments are formed and how legislation passes, but MPs are also expected to exercise independent judgment. All of that means that there is no simple or obvious answer to the question raised by the petition of whether the current arrangements already strike the right balance between representation, independence and accountability, or whether there might be merit in exploring alternative mechanisms.

What is clear from the petition is that many members of the public care deeply about the relationship between voters and their representatives, how it works in practice and whether they feel that they are being represented in this place. I very much look forward to hearing the views of Members from across the House.

--- Later in debate ---

[Dr Savage]

At the start of the debate, I suggested that we might make up for lack of quantity with quality, and I think we have delivered on that promise. I thank colleagues from across the Chamber for their most thoughtful, fascinating and wide-ranging contributions to the debate. I especially thank my hon. Friend the Member for Hazel Grove (Lisa Smart) for her interesting diversion into the many other ways in which we could help to restore faith in our democracy, such as a fairer voting system and House of Lords reform.

I echo the regret expressed by a number of colleagues that parliamentary procedure precludes the Chair from jumping into the conversation. I am sure that that would have been a most fascinating—

[Lisa Smart]

Hour.

--- Later in debate ---

[Dr Savage]

Yes—but I believe that this Chamber will be available until at least 7.30 pm, so perhaps we could have an impromptu seminar.

I trust that Mr McIlhinney and the other signatories to the petition will feel that we have done justice to their concerns and will appreciate the calibre of the debate, even if the constituencies that I mentioned at the outset are not going to be dusting off their ballot boxes any time soon. I thank everyone present for their most valuable contributions.