Diego Garcia Military Base and British Indian Ocean Territory Bill

Baroness Goldie Excerpts

Report stage
Monday 5th January 2026 Lords Chamber

The implications on maritime and nuclear security in the context of these dangerous and alarming concerns, coupled with a rapidly changing geopolitical space, cannot be overstated. For this reason, my amendment stipulates that the Secretary of State must bring a report to Parliament that contains the opinions of the naval staff of all three AUKUS partners.

[Baroness Goldie (Con)]

My Lords, I endorse the comments of my noble friend Lord Callanan on the amendments in this group. I raised specific concerns about defence and security in Committee, and I have considerable sympathy with the remarks of my noble friends Lord Lilley and Lord Leicester on their amendments. I accept that the Minister has acted in good faith in repeating the advice that he has been given.

After the Committee debate on these defence and security issues, I read Hansard and the Pelindaba treaty with care. It seems that, as my noble friend Lord Lilley indicated, once UK sovereignty over the base is relinquished in consequence of this treaty, that sovereignty transmits to Mauritius and the base is then subject to whatever international agreements Mauritius has entered into. There are restrictive consequences for the base from the Pelindaba treaty, but my concern is slightly broader than that of my noble friend Lord Lilley. If, in the eyes of the other signatories to the Pelindaba treaty, Mauritius is deemed to be in breach, all the other signatories have a locus to raise an objection and deploy international law. That cannot be addressed unless this treaty is renegotiated to retain sovereignty of the base in the hands of the UK, and I wish to place on the record that that is my opinion and understanding of the position.

The Minister rightly does not wish to be drawn into discussing sensitive operational issues relative to the base, and I agree with that. However, before stage 3, I ask him to ask his officials to draft him a letter to be placed in the Library, explaining how the renunciation of sovereignty of the base by the UK and the acquisition of that sovereignty by Mauritius, then governed by the Pelindaba treaty, is compatible with free and unrestricted usage of the base by the US, the UK and our allies.

The Minister has been placed in an impossible position by his Prime Minister: this treaty was negotiated on a basis far removed from the harsh reality of the world we live in. Defence and security seem to have become incidental sacrifices to the worship at the high altar of heady diplomacy and international jurisprudence. It should never have proceeded as it did and, for that, I do not blame either of the Ministers sitting opposite, but I want the Minister to explain how the Government will fix it.

[Lord Morrow (DUP)]

My Lords, I wish to make some comments on Amendment 22 in my name, and I will seek not to transgress my time in relation to this one.

In Committee, the noble Lords, Lord Lilley and Lord Callanan, and the noble Baroness, Lady Goldie, pointed out the difficulty arising from the fact that while the Mauritius treaty makes provision for the leasing of Diego Garcia by the United Kingdom, this does not change the fact that in the event that the Mauritius treaty is ratified, Diego Garcia would come under the sovereignty of Mauritius.

This is problematic for two reasons at least. First, the Republic of Mauritius is a signatory to the Pelindaba treaty, which means that no nuclear weapons can be held in the territory over which it is sovereign. Secondly, Article 7 of the Mauritius treaty expressly states:

“Each Party confirms that none of its existing international obligations or arrangements now in force or effect between it and any third party is in conflict with the provisions of this Agreement, and that nothing in this Agreement shall affect the status of existing international obligations or arrangements except as expressly provided for in this Agreement”.


Can the Minister confirm—I know the noble Baroness, Lady Goldie, has already made reference to this—that the Government have discussed this matter in its entirety with the Government of the United States and that they have confirmation from the US that they have secured their solemn pledge that no nuclear submarines or other nuclear weapons will be able to be taken to Diego Garcia if sovereignty is transferred?

I look forward to hearing what the Minister has to say on that point. But I very gently say that while of course he must not discuss operational matters, this cannot be pushed as an excuse for dodging questions about compliance with international law. Any attempt to deploy that stratagem, to the point of avoiding the demonstration of compliance with international law when non-compliance is feared, would form a deeply troubling precedent.