SNP Westminster leader Angus Robertson criticised Mr Cameron, Deputy Prime Minister Nick Clegg and Labour leader Ed Miliband, saying none of the three party leaders would be taking part.
It comes after the three men pledged further devolution - including giving Scotland important powers over tax and welfare - in the run-up to last month’s referendum, in which voters north of the border rejected independence.
Scottish Secretary Alistair Carmichael said the debate was “more than just business as usual” but insisted it was “not strange at all” that the Prime Minister would not be speaking in it.
But Mr Robertson recalled the “solemn promise and vow that was given by the three UK leaders to voters in Scotland shortly before the referendum on extensive new powers”.
The SNP MP told BBC Radio Scotland’s Good Morning Scotland that Mr Cameron “can’t even be bothered to run up to lead the debate about what he says is an important issue”.
Mr Robertson said: “At Westminster, as is the case in the Scottish Parliament, when there is very important business before the House it is the Prime Minister, or in Scotland the First Minister, that leads those important debates.
“That was the case just over a week ago on the developments in Syria and in the debate today we are not going to see the debate led by the Prime Minister, or the Deputy Prime Minister or the leader of the Labour Party, the three people who signed the solemn promise, the vow, that we should have extensive new powers.
“If they don’t even think it’s important enough to turn up and lead the debate, how should anybody in Scotland have faith that what we’re going through is anything but an exercise in trying to get themselves to the next UK general election?”
Mr Robertson said the three UK parties were “back-pedalling” on their commitment to further devolution and “are more interested in having a debate about English votes so they can have a party political advantage in the next UK election”.
But Mr Carmichael told the same programme it was “quite unusual for the PM to lead a debate”.
The Liberal Democrat Scottish Secretary said: “The way he does it is - this is a country that has a cabinet government, it’s not a presidency - is that the ministers who are responsible for any particular area of Government policy, on this occasion it’s William Hague who chairs the government committee on devolution, and myself will be leading and responding to the debate.”
He continued: “It’s not strange at all, this is just how it works. The Prime Minister will be available for questioning by MPs tomorrow afternoon when he comes to the House for Prime Minister’s Questions. The debate itself will be led by the ministers who are in charge of the area, William Hague and myself and that’s just business as usual.”
Mr Carmichael argued it was “a little bit desperate” for the SNP to claim Mr Cameron was not committed to increasing Holyrood’s powers.
“He was very much engaged in the referendum campaign, he made an intervention at the earliest possible stage after the result,” the Scottish Secretary said.
But he said the Conservative leader was “not going to do everything”, adding: “This is not a Government that is just restricted to the man at the top. We have a cabinet government and we share the responsibility, we share the load.
“I suspect that if it was the other way round, you would have got the Nationalists putting out a press notice saying why is David Cameron controlling it all? Doesn’t he trust his ministers to do the job?”