A new Great Reform Act is needed to limit the absurdities of our constitution

As vilified, unpopular and mediocre as many of our politicians are, it will fall to this generation to construct a new constitutional settlement for the United Kingdom. In some respects, the work is under way: our MPs have begun to tackle the extent and shape of further devolution in Scotland and so-called “English Votes for English Laws”. As soon as Friday they may be called on to investigate how a legitimate government can be formed in the Commons when no party or plausible combination of groups can command a majority. And beyond the horse-trading that will follow the election, the House of Lords and the electoral system itself require urgent renovation.

The constitution we now have – part written in law, part codified in a sort of Haynes manual written by Gus (now Lord) O’Donnell, part governed by conflicting precedents, and part made up as we go along – cannot cope with today’s challenges. Quite an agenda, and, prospectively, the biggest constitutional upheaval since the Great Reform Act of 1832. The New Great Reform Bill needed in the next parliament will require seemingly incompatible parties to work together, and supposedly unbreakable pledges to be bent. Perhaps it will be too much for one Bill in one parliament, but the work has to start now.

For the sake of stability, the fixed-term parliament should be abolished through a cross-party consensus, and the previous, though flawed, prerogative granted to a prime minister to request the dissolution of parliament restored. Of course, if the nation remains stubbornly determined to keep voting in hung parliaments, that might lend less rather than more stability to things; which is why we also need to restore faith and inject logic into the electoral system.

If we have to have hung parliaments in future, then they should bear a closer resemblance to the will of the people. That would help prevent the odd situation where the party with the largest number of votes will not always win the largest number of seats.

Even at this stage, we know what outrages will be perpetrated by the first-past-the-post system. The SNP, on about half of the Scottish vote, could win almost every seat, giving the dangerous impression that Scotland is a unanimously nationalist state. Ukip and the Greens will score many millions of votes and be rewarded with few MPs. Their voters will feel disenfranchised. As will Conservatives in Manchester and Leeds and Nottingham; and Labour supporters in Surrey and Dorset. So the debate will begin in earnest, in a way that it failed to during the referendum on the alternative vote system four years ago.

So far as the future of the Union is concerned, Boris Johnson is correct in saying we need a “grown-up debate” on a federal Britain. Asymmetric devolution, with differing powers devolved to Scotland, Northern Ireland, Wales, London and other places can be made to work, as it does, after a fashion, in Spain. The position of “England” is complicated, but it seems fair that English MPs should have the final say on legislation that affects only England. Alternatively, a reformed House of Lords could be turned into a sort of Senate, but the usual problem of a competing democratic mandate to the Commons remains. An option is complete abolition, with stronger select committees to provide the revision and checks and balances the Lords provides, and the Supreme Court taking on a constitutional arbitration role.

All this is necessarily sketchy. Yet we cannot have the stable government we need to tackle still formidable social and economic problems without a new constitution that commands respect and broad support. Whether the 650 men and women we will elect this time are up to the task we shall soon discover.