Forget devolution, the only thing that matters in Westminster is the next General Election

It is in the Conservatives’ interests to stop Scottish MPs voting on English matters

Members of the media listen to British Prime Minister David Cameron’s speech on the Scottish referendum (EPA)

Within hours of Scotland delivering an answer, David Cameron posed another question: What to do about England? And he offered his solution.

Cameron said that as well as delivering new powers for Scotland he would seek other reforms at the same time, including distinct powers for MPs from England in relation to English legislation. The Prime Minister added that the entire package of changes would be ready within months.

Apparently we move on from years of agonised or convenient paralysis to draft legislation by January.

Let us recall what Gordon Brown pledged for Scotland, with the agreement of the party leaders. Brown promised that a motion would be moved in Parliament to agree extra powers for Scotland, focusing on income tax, housing benefit and welfare assessments. There would be agreement by St Andrew’s Day (30 November), and a Bill would then be presented to Parliament in the new year and voted on by Burns Night (25 January).

Cameron has now added that, by then, the package must include sweeping reforms for the rest of the UK. He had no choice but to do so. Conservative MPs would not have let him get away with handing over powers to Scotland without addressing the English question.

It is also in his wider electoral interest to do so. Do not expect Cameron to say very much more about Scotland now that the votes in the referendum are safely cast. Expect him to say a huge amount about England. Although the Scottish leader of the Conservatives, Ruth Davidson, is closer to the idea of a genuine moderniser than is Cameron, her party is as toxic as ever in Scotland.

The referendum is over and the general election follows. Cameron needs to win in England. Cameron is a smart choreographer of politics, conjuring the Coalition from nowhere when he failed to win an overall majority at the last election and now announcing a constitutional revolution for the whole of the UK to be agreed speedily. But his proposals for the constitution form an even higher bar compared to the one he leapt over to create a coalition.

When Cameron joined the other party leaders in making his “vows” to the Scottish voters, he did not add that they would only get their powers as part of a package for England.

Cameron has every right to raise the England question, but to incorporate his proposed solution into precisely the same timetable for Scotland is a very big addition to the original vow. For the Scots, it is the equivalent of buying a house only to discover the deal will go ahead when a blazing row over planning permission nearby is resolved at the same time.

Of the many obstacles to meeting the ridiculously tight deadline, there is one that stands much higher than all others. Constitutional reform is not an abstract complexity. Changes can make or break parties. Party interest plays an overwhelming part in determining support or opposition to reform. No leader calculates that “this reform will harm my party, but I will support it out of principle”.

David Cameron signed a “vow” to continue the “Barnett allocation of resources” across the UK (EPA)

It is in the Conservatives’ interests to stop Scottish MPs voting on English matters. Labour would be a loser if such a change were made, which is why it focuses on more powers for local government.

With an early-morning flourish, Cameron hopes to prevent progressive policies being implemented in England – whatever the result of the UK election – and to cement in England at least his party’s ongoing Thatcherite revolution. Meanwhile, if the UK elects a Labour government, a Labour PM might be able to dictate foreign policy while being powerless to implement key economic policies and public service reforms in England. The stakes for both sides are high.

Cameron’s suddenly partisan pitch might help him electorally and presents Ed Miliband with one of several acute dilemmas as he seeks to recover from his peripheral role in the referendum campaign.

But the English question will not be answered so easily. I would be very surprised if a clear, watertight, lasting definition of “English legislation” can be fashioned in the space of just a few weeks.

To take just one example: some of the current public service reforms imposed on England alone had funding implications for Scotland. On that basis, would Scottish MPs have got a vote or not if Cameron’s proposals had been in place? And does it help the cause of representation if some MPs are less significant than others? Who in Scotland would want to stand for the UK Parliament? That is the problem with answers to the English question. They generate more questions.

But little of this is about the constitution. The Conservatives want to rule in England or stop Labour from doing so. Labour also wants to rule in England and to block moves that might prevent it from doing so. I am not even sure the referendum in Scotland was entirely about the constitution. It was about lots of different conflicting hopes and fears, which is why two opposing leaders, Cameron and Miliband, could both express their delight at the result.

Very quickly that result has become a distant factor in their calculations. The debate now is about future power. There will be no consensus. There is no worse time to generate such a debate than a few months before a general election. Indeed, this is partly about parties framing a debate in order to win the general election.