GORDON Brown has piled pressure on the Labour leadership not to back the call from Conservatives and Liberal Democrats for all income tax powers to be devolved to Holyrood.

The former Labour Prime Minister branded such a move anti-Scottish and anti-British, which would lead to the SNP achieving independence through the back door.

Labour appears split on the issue of income tax, with some party figures wanting all of it transferred to Edinburgh. But last night one senior party source stressed how Mr Brown spoke for the overwhelming majority of Labour MPs.

In a Commons debate, the MP for Kirkcaldy and Cowdenbeath said he wanted to be constructive and suggested there were many extra devolved powers, from housing benefit and attendance allowance to the conduct of elections, which all the parties could agree upon.

He stressed how there was also agreement that more tax powers should be devolved and suggested the best way forward was for 75 per cent of income tax plus 50 per cent of VAT revenues be transferred to Holyrood. This way, he explained, the test of accountability would be met and the Scottish Parliament would raise the majority, some 54 per cent, of what it would spend.

But Mr Brown attacked Prime Minister David Cameron for causing a constitutional crisis in the making with his statement proposing English votes for English laws, which would restrict the voting rights of Scottish MPs.

Mr Brown said: "The proposal to devolve 100 per cent of income tax and then exclude Scottish MPs from voting on income tax at Westminster is anti-Scottish because by excluding Scots from voting on key matters it makes them second class citizens in the House.

"But it is also anti-British because, by abandoning income tax as a shared tax, it threatens to end the pooling and sharing of risks and resources that underpins the unity of the UK and it looks like the Trojan Horse for fiscal autonomy, which would split the Union and enable the SNP to get through the back door what they cannot get through the front door."

The ex-PM argued there could be a sensible accommodation on exclusively English Bills, suggesting, a change in committee procedures as legislation passed through the Commons, where English MPs formed the detailed scrutiny stage but later stages could be voted on by all MPs.

However, he insisted having two classes of MP would hobble government because it would become the "servant of two masters; not sure whether its continuation depended from one day to the next on English votes or on the votes of the whole of the United Kingdom".

He also claimed such a system would mean no MP from a Scottish constituency would ever again be Chancellor or Prime Minister.

For the Government, Scottish Secretary Alistair Carmichael said the referendum vote had been decisive: Scots wanted to remain within the UK and "not that the question should be asked again in three years". He criticised the SNP for "manoeuvring now for that outcome".

Peter Wishart, the Nationalist MP for Perth, noted how MPs had signed a parliamentary motion for a debate, demanding a review of the Barnett Formula, and asked: "Is Barnett safe?"

The Scottish Secretary insisted it was because it was in the three leaders' vow and told Mr Wishart: "I caution him. He says that somehow the Prime Minister, the Leader of the Opposition, the Deputy Prime Minister were not acting in good faith. He seeks at every turn to undermine confidence in the vow.

"If he is still wanting to pursue the cause of independence, if he wishes not to accept the verdict of the people of Scotland, then that's fine. But if he and his party are taking part in the Smith Commission in good faith, then, frankly, they should accept all of us are doing so in good faith."