Conservative MPs have urged review and reform of the Barnett formula hours after David Cameron insisted it was not "on the horizon".
The Prime Minister pledged to maintain the controversial method of allocating spending to Scotland, Wales and Northern Ireland in a joint vow with other party leaders at end of the Scottish referendum campaign.
Quizzed by MPs on the Commons Liaison Committee, Mr Cameron said there was no "massive pot of gold" for England in reforming the mechanism.
But in the main Commons chamber, Tory MPs condemned the 1970s-scheme and dozens have signed a motion calling for the Government to "include a review of the Barnett formula" in proposals for English devolution.
Introducing the motion, Tory Dominic Raab (Esher and Walton) said: "A new deal for Britain must be fair to all parts of Britain.
"In my view, that really means two things - first, if we went down the proposal to devo-max or fuller financial devolution that would eventually render the Barnett formula, used by the UK Government to subsidise devolved administrations across the Union, as utterly untenable.
"That formula is based on out-dated spending patterns and population numbers already divorced from any objective assessment of real need across Britain.
"Scotland wants greater powers to tax and spend - and as I've said, I'm sympathetic - it cannot expect the rest of the Union and taxpayers across the Union to keep subsidising them to the hilt on such an arbitrary basis without fuelling resentment in other parts of the UK.
"I note actually that is also the logic of the SNP submission to the Smith review."
Tory MP for St Albans Anne Main said her constituents deserved good services as much as those in Scotland, insisting they were concerned about the deal offered north of the border.
She said: "The Barnett formula - to quote Lord Barnett himself - is unfair, should be stopped, is a mistake.
"I do not think we should scrap the Barnett formula but we should certainly review the Barnett formula... in my constituency we have, unfortunately, far less money spent on my constituents.
"I find it hard to justify to them when I have areas of multiple deprivation that they get some 11% below the UK average and 23% below Scotland and 28% below Northern Ireland.
"My constituents don't understand how they are net contributors to the Chancellor's coffers and do so badly when they are trying to get services... they are as much in need of services as any other MPs' constituents.
"It is hard to do that when the formula is skewed the way it is - we should look at it and review it."
Labour's George Howarth (Knowsley North and Sefton East) also raised the Barnett formula in the debate, broadly on devolution and the Union, which was scheduled by the backbench business committee.
He said: "I don't personally... have any difficulty with the Barnett formula. What I want is a Barnett formula for England, or some equivalent to it.
"The issue is how you get a fairer distribution of resources."
Liberal Democrat Alan Reid (Argyll and Bute) said: "Of course constitutional change must be fair to the whole United Kingdom and I am sure in the coming years we will see further progress on devolution for the other regions and nations in the United Kingdom.
"But further powers for the Scottish Parliament must not be held up while those debates take place in other parts of the United Kingdom.
"The vow made in the run up to polling day was that the Barnett formula would continue... I think any reasonable person would interpret that to mean continue as it is."
Angus Robertson, the SNP leader in Westminster, said: "The SNP and the Scottish Government continue to believe Scotland should, and in the future will, be independent.
"However, we accept both the result of the referendum on September 18 and that independence will not be the outcome of the Smith Commission.
"What is beyond doubt though is the people of Scotland expect early and substantial change, not something that is dependent on English votes for English laws, much as I have sympathy for that as an issue, or indeed on the West Lothian question, or the subsidy argument we hear from the other side.
"Change that will give the Scottish Parliament the further powers and responsibilities it needs to tackle the challenges facing Scotland in a way that responds to the views and votes of people in Scotland.
"That is what was promised in the referendum campaign and it is what people now expect to be delivered - without any conditions."
Labour's Paul Flynn (Newport West) asked Plaid Cymru Hywel Williams (Arfon): "We've all heard some worrying suggestions here that the vow that changed the result of that referendum in Scotland might not be honoured fully.
"If that's not done won't it invalidate the effect of the vote and entitle people to ask for another vote?"
Mr Williams replied: "On Scotland, I think you're entirely right."
Shadow Commons leader Angela Eagle said: "There's been a consistent drumbeat that we need to have more and better sharing of powers from the centre to the cities, the counties, the regions and the nations of this country and we need to enhance real democratic involvement - not watch it diminishing in reduced involvement and cynicism."
She said the "vow" from the main Westminster leaders has "never been or will be in doubt".
Ms Eagle asked MPs to vote against the amendment moved by Mr Raab as its reference to review the Barnett formula would "go against the promises" given to Scots during the referendum.
Replying for the Government, Commons Leader William Hague said: "Many MPs including (Ms Eagle) have referred to the sense of alienation and sense of powerlessness which many voters and observers of politics feel and I think that is true.
"And it's very important we grasp that, that we respond to that - I think it will be important following up this debate that in the coming months we have further detailed and substantial debates in this House about these issues."
He said Lord Smith is overseeing a cross-party process that will publish an agreed set of proposals by the end of the month.
The motion debated was not moved to a vote as it was talked out by Mr Raab.