Britain’s main political parties are heading for a pre-election clash over the introduction of English votes for English laws after the Labour party announced that it would boycott a “Westminster stitch-up” on the issue.

As a Commons debate opened on the consequences of the no vote in the Scottish referendum, the Labour party announced that it would refuse an invitation from William Hague to contribute to the work of a cabinet committee.

A Labour spokesperson said: “We will not be participating in a Westminster stitch-up. We think we need a constitutional convention so we can hear from all voices in England.”

The move by Labour came as Alex Salmond predicted that Scotland could “exact revenge” on the Westminster parties at the ballot box, because a “huge gap” had opened up between their proposals for greater devolution for Scotland and what they promised on the eve of the independence referendum.

The outgoing Scottish first minister said that devolution plans, set out in a new command paper on Monday by the Scotland Office, were “weak”. Alistair Carmichael, the Scotland secretary, said that the paper was designed to explain the proposals of the three main UK parties and would be considered by the independent devolution commission chaired by the crossbench peer Lord Smith of Kelvin. The SNP and the Scottish Green party have seats on the commission.

The criticism from Salmond came as Labour and the Liberal Democrats appeared to be lining up to oppose Tory tactics over plans to answer the West Lothian question, which asks why Scottish MPs at Westminster should be able to vote on health and education in England while English MPs have no say over these policy areas in Scotland.

William Hague, the leader of the Commons, is chairing a cabinet committee that will examine proposals to introduce English votes for English laws, known by its acronym of Evel, at Westminster. Hague has said that if the main UK parties fail to reach agreement by the end of next month a vote should be held in the Commons to ask MPs which proposals to adopt.

The Lib Dems, who have seats on the cabinet committee, agree that it is right to limit the ability of Scottish MPs to vote on English-only matters. But they say that a committee of English MPs, which would have a veto over such legislation, should be appointed on the basis of the parties’ overall vote share rather than the number of MPs they have at Westminster.

Nick Clegg told the Commons before the devolution debate that he agrees with Labour’s proposal for a constitutional convention to discuss the highly contentious issue. Under Labour’s plans this would be appointed in the autumn of next year, allowing Ed Miliband to form a UK government after the general election, with the support of Scottish Labour MPs, if he emerges as leader of the largest party.

The differences between the main UK parties emerged after Salmond warned that plans for greater devolution did not go far enough. The Scottish first minister told the BBC’s Radio 4 Today programme: “There is a huge gap that is emerging between the vow – the last-minute, desperate promise made under the guarantee of Gordon Brown by the three Westminster leaders – and what was suggested in the command paper, which was just a regurgitation of what has been indicated last spring, promises which were so weak they hardly featured in the no campaign.

“Right now, the initial judgment that’s coming from Scotland is that people have no confidence in Tory guarantees and are absolutely fizzing about what looks like a preparation for a betrayal of a strong commitment made.”