The referendum on changing Britain's voting system could be delayed until the autumn of next year by a Conservative backbench revolt.
Tory opponents of electoral reform will join forces with Labour MPs by tabling an amendment to the Bill calling the referendum, saying that it should not be held next May, but in September or October next year. That would be a setback for Nick Clegg, who fought hard to secure the 5 May date.
Tory supporters of the existing first-past-the-post system believe there is little chance of the Commons passing a wrecking amendment requiring 40 per cent of the electorate to endorse a switch to the alternative vote (AV) in the referendum. The coalition agreement between the Tories and Liberal Democrats promised that a "simple majority" in the public vote would be enough. However, the deal made no mention of timing and so many Tory MPs are said to be ready to vote for a delay.
Critics believe it is wrong to hold the AV referendum on the same day as elections to the Scottish Parliament and Welsh Assembly. George Eustice, Tory MP for Camborne and Redruth and an organiser of the "No" campaign, said: "There are issues of fairness in a differential turnout in Scotland, Wales and England. There are entirely separate legal spending restrictions between referendums and national elections."