“OUR political system is broken.” That blunt verdict on British democracy is not taken from a protest banner. It is the position of David Cameron's coalition, set out in the programme for government drawn up after the 2010 general election. To that bleak diagnosis, the programme adds a prescription: fundamental political reform, starting with a referendum on May 5th on whether to change the voting system used for elections to the House of Commons (see article).

This newspaper agrees that British democracy is in need of repair work. Public suspicion of politicians—though hardly unique to the British Isles—is high. Flaws in the current voting system of first-past-the-post (FPTP) have contributed to a dangerous sense that British voters have too little sway over those who govern them. We would, therefore, support a change to a better voting system. Unfortunately, the one on offer isn't.

The way things are

The current system has virtues, as well as flaws. One is simplicity: voters place a cross next to one name on the ballot, the candidate who secures the most crosses wins. It allows for ideological clarity, and thus accountability. Historically, FPTP has favoured the election of majority governments, able to defend a clear programme or face ejection at the next election. In much of Europe, where coalitions are the norm, political compromise is seen as a virtue. The very word has an unhappy ring in Britain: just now, lots of Lib Dem voters feel compromised by coalition with the Tories, and not in a good way.

Yet more than half the current MPs hold seats deemed “very safe” or “ultra safe”, leaving millions of citizens feeling that their votes change nothing. And, with support for the Conservatives and Labour falling, the number of MPs elected by a minority of votes cast in their seat has risen. Above all, FPTP is not very representative, disproportionately rewarding parties whose support is geographically concentrated. That makes Britain look more divided than it really is. Today's rules punish Conservative supporters in the north, Labour voters in the south, and Lib Dems everywhere. At the general election Britain's third party picked up nearly a quarter of all votes but fewer than one in ten seats: small wonder that the Lib Dems loathe FPTP, and made a referendum on ditching it a key demand before joining the Tories in a coalition.

What Lib Dems really want is a system that would give them seats in proportion to their votes. That would leave them with a good chance of playing kingmaker in an endless series of left-leaning or right-leaning coalition governments. But because Conservatives fear that they would not win an outright majority in a proportional representation (PR) system, the Lib Dems could secure only a more modest prize: a referendum on keeping FPTP or adopting the alternative vote (AV).

Under AV voters would be invited to rank candidates on the ballot in order of preference. If after a first round no candidate had more than 50% of the votes cast, the votes of the least popular candidate would be redistributed, following the second preferences indicated by supporters of that eliminated candidate. Rounds of redistribution continue, using third, fourth or lower preferences if needed, until someone crosses the 50% line. Along with the Lib Dems, the Labour leader Ed Miliband and affable celebrities such as Colin Firth want AV; the Conservatives and many Labour MPs oppose it.

The experience in Australia, which has used AV since 1918, suggests that it would not be a disaster. The system is not widely disliked; indeed, it is not an issue. But Yes campaigners make greater claims for AV than that. They say it would force “lazy” politicians to “work harder” by reducing the number of safe seats. Because politicians would need to seek more than 50% of votes to win, they would become less tribal.

They are right that AV would probably favour consensus-seeking, centrist candidates. A University of Essex study estimates that the Lib Dems would have scooped 32 more seats if AV rules had applied at the general election. But there would still be lots of safe seats under AV. It is not a PR system (the Lib Dem leader, Nick Clegg, used to call it a “miserable little compromise”). Indeed, in a landslide, AV can exaggerate the swing to the winning party. Many MPs would still be elected by a minority of votes cast, because the version on offer allows voters to give their favourite a “1” and stop there, turning AV into a messy version of FPTP. What's more, if there is a run-off, a carefully considered first preference carries the same weight as more tepid second or even third choices. And it encourages voters to flirt with extremists, knowing they can make centrist parties their second preference. AV is not an improvement.

Our first preference

Some Yes campaigners admit that AV has flaws but argue that changing the system once will make future changes easier. Perhaps, but not certainly so. It might exhaust the national appetite for reform. And so large a change should be undertaken only for a system that can be defended on its own merits.

For this newspaper, that system would have to be genuinely more proportional than the current one. We would not support undiluted PR, which often means party barons choose who forms a government, and (as in Israel and Germany) hands too much power to small parties. But a dose of PR, to elect, say, a fifth of MPs, would go a long way towards correcting the current system's unfairness—especially if the top-up MPs were selected on a regional basis. In Scotland, where over 40% of the seats are chosen this way, there has been a string of minority or coalition governments. We would stick with FPTP for all but 20% of the seats to increase the likelihood of strong, accountable governments. Call the combination “FPTP Plus”.

For supporters of constitutional reform, such as this newspaper, these are good times. The previous government introduced a freedom of information act. An overhaul of the House of Lords is under way. But this referendum is a disappointment. AV would not be a disaster, but it would not be an improvement either; and although we are reformers by instinct, we do not believe in change for change's sake. The Economist would therefore vote No.