Everybody agrees that having an un-elected house is archaic. Furthermore, the FPTP voting system for the Commons means that our governments are not often very representative. Changing our voting system for the commons may not be necessary with a different upper house.
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The type of proportional representation used is up for debate, as are the powers that a new upper chamber would have and other details like how long terms would be etc.
Many people like our FPTP voting system for its simplicity and for producing a local representative. Having an upper house elected proportionally allows for greater representation and local representatives.