David Cameron has accused Labour of "not being interested in fairness" for the UK after it decided to boycott talks on English votes for English laws.

Ed Miliband's party denounced the talks being led by Leader of the Commons William Hague as "a closed-shop stitch-up" when "proper reform" is needed.

But the Prime Minister rejected the suggestion that he was playing politics with the Union following the vow made to the people of Scotland during the referendum campaign.

He said: "What we need is obviously more devolution for Scotland but a settlement that's fair for the whole of the United Kingdom.

"I think it's a matter of great regret if Labour are going to walk out of this Cabinet committee which they could join in and make their suggestions.

"But obviously they are not interested in fairness across the United Kingdom so we will have to work hard with other partners to make sure we deliver."

The row blew up as MPs in the House of Commons debated the promise of more powers for Scotland, amid nationalist claims that Westminster politicians are "back-pedalling" on promises made ahead of last month's independence referendum.

Mr Cameron angered Scottish nationalists on the morning after the failed independence vote, when he said that the implementation of further devolution north of the border should go "in tandem with" moves to resolve the long-standing question of whether Scottish MPs should be allowed to vote on laws which affect only England or England and Wales.

He tasked Mr Hague with chairing a Cabinet committee to draw up a way forward, and the Commons Leader invited other parties to take part in discussions.

But a Labour source has confirmed the party will not take part, saying: "We need proper reform, not a closed-shop stitch-up in a Cabinet room."

Mr Miliband's party has called for a swift transfer of powers to Edinburgh, along with the establishment of a constitutional convention to look at the wider issues raised by devolution.

Opening debate in the Commons, Mr Hague indicated the Government could be open to a convention, but not if it delayed immediate discussions and decisions.

He said: "The Labour Party can come to the Cabinet committee and put that forward - but they seem unwilling to do so.

"Indeed, the Government will consider the proposals for the establishment of such a body on the right terms and at the right time. It's my view there is merit in this ...

"But no one is suggesting delay in the commitments we have made to Scotland in order to wait for a constitutional convention. No one is suggesting delay in the amendments we make to the Wales Bill and other commitments to Wales. Equally, it is right to address the needs of England without delay in the coming months and that is why we propose to do so."

Mr Hague warned that "insensitivity and indifference" to concerns over the English votes issue risked the future of the United Kingdom.

"I know there are MPs who argue that to address this question is to somehow put the United Kingdom itself at risk but I say to them the United Kingdom is in greater danger if the legitimate arguments and expectations of English decision making, on decisions effecting only England, are not responded to," he said.

"Insensitivity and indifference is the danger to the union in all nations including in England."

Scottish National Party leader Alex Salmond said Mr Cameron was already "reneging" on pledges made during the referendum campaign.

"The Prime Minister started the process of reneging on the commitment when he came out of Downing Street hours after the referendum and said that progress in Scotland should be in tandem with ... constitutional change in England. Even Gordon Brown is finding it difficult to stomach," he told BBC Radio 4's Today programme.

The First Minister also indicated that he did not view another referendum as completely off the agenda.

"What I said was that the referendum was a once-in-a-lifetime opportunity," he said.

"My view is that constitutional referendums came along once every political generation - about every 20 years or so.

"Circumstances obviously can change. Clearly, if you had a situation where three leaders made such a public vow - not even a political promise but a vow - in the last few desperate hours when they thought they were losing the referendum campaign and then reneged upon it, then that would obviously be a very, very substantial change of circumstances.

"These matters ultimately are for the people of Scotland to decide. It is for the people of Scotland to decide whether it is satisfactory to be conned and tricked by Westminster leaders, or they will exact a revenge at the ballot box."

Mr Hague said Mr Salmond was "almost looking for and hoping for some sense of betrayal".

The Tory minister told Today: "Let it be very clear that every commitment made by not only the Conservative but Labour and Liberal Democrat parties about what would happen if the result of the Scottish referendum was No, every commitment has so far been kept and will be.

"We have said, the Prime Minister and I have said, that those things should go in tandem. But they are not tied in the sense that one is dependent on the other.

"The commitments to Scotland are unconditional and will go ahead - this is an absolute 100% clear commitment that will go ahead whatever we decide or don't decide about England.

"But it is our view that fairness to the whole of the UK means the party should also agree on the same timetable the consequences for Scottish MPs voting on English matters.

"If they can't, then of course it will be a matter we all debate in the general election campaign. This is a democratic country. The people will decide."

Lib Dem minister David Laws, who sits on the devolution Cabinet committee chaired by Mr Hague, said: "The Liberal Democrats are determined to resolve the matter of English and Welsh votes on English and Welsh matters but this must not be a politically-motivated stitch-up by the Conservatives.

"The Tories have a majority of MPs in England but got less than 40% of the vote at the last election. Any solution to this matter must reflect the will of the voters, not the entrenched advantage the electoral system gives the Conservatives in England.

"Whether it is in Scotland, Wales, Northern Ireland or London, every time Westminster has devolved power it has been on a proportional basis and this must be consistent with that approach.

"That is why the Liberal Democrats have proposed a grand committee system to allow English MPs, appointed proportionately, to vet laws that will apply only in England, joined by Welsh MPs when matters affecting Wales are debated."