GORDON Brown has declared that a Home Rule settlement for Scotland could kill off the SNP’s bid for a second independence referendum.

The former prime minister said his proposal for a “more federal” relationship between Scotland and the UK as it left the European Union could win overwhelming support from up to 80 per cent of Scottish voters.

READ MORE: Gordon Brown backs effective Scottish Home Rule, saying Brexit vote calls for new constitutional settlement

Mr Brown set out details of the “more innovative constitutional settlement,” involving yet more powers for Holyrood on issues like agriculture, fisheries, the environment and employment rights, ahead of his appearance at the Edinburgh International Book Festival.

He said that while voters had to accept the EU referendum result, the new circumstances required a “constitutional breakthrough that transcends the sterile stand-off between a non-change conservative unionism and an unreconstructed nationalism”.

The Labour grandee described the recent slew of devolved powers to Holyrood such as on tax as “already out of date” given the result of the June 23 vote.

READ MORE: Gordon Brown backs effective Scottish Home Rule, saying Brexit vote calls for new constitutional settlement

His new proposal includes examining the case for transferring powers directly from Brussels to Holyrood instead of Westminster, boosting Scotland’s funding settlement by as much as £750 million a year, and reserving only specific powers such as on currency, defence and security and pensions to London while all other powers could be devolved to Edinburgh.

Asked during the festival event if such a plan could prevent a second vote on independence in Scotland, Mr Brown replied: “The solutions I am proposing can avoid that.

“I am not convinced that people want independence but I do know people are frustrated by the outcome of the European referendum.

“We have got to show people who voted Yes that there is a better way forward. There are 45 per cent of the population who voted Yes, many of them are younger people who will need to be convinced.

READ MORE: Gordon Brown backs effective Scottish Home Rule, saying Brexit vote calls for new constitutional settlement

“I personally have never thought that all the people who voted Yes wanted independence in the way the SNP described it.”

The former PM added: “I believe now if we have a positive alternative, something similar to what I am proposing, it is capable of winning 75 to 80 per cent support.”

Nicola Sturgeon has said a second independence referendum is now “highly likely” following the EU referendum result after Scots voted overwhelmingly to Remain.

The First Minister has pledged to look at all options to protect Scotland’s place in Europe but has already began preparing legislation for another independence vote if it proved to be “the best or only way” of achieving this.

But Mr Brown argued that the SNP leader and her colleagues had failed to make the case for independence, arguing that the Nationalists were now proposing ending both a political and an economic union, which in the latter case could mean a hard border being erected between Scotland and England.

He stressed that serious questions over currency, pensions, borders and Scotland’s deficit of £15 billion remained.

Last week, the Government Expenditure and Revenue Scotland figures showed that the Scottish fiscal deficit had for 2015/16 grown to 9.5 per cent, which is larger than that of Greece at 7.2 per cent; while the UK’s had shrunk to four per cent.

“I don’t think they have any solution to the fiscal gap, which is around £15bn, which is big enough to double the rate of income tax in Scotland if you want to maintain the same level of services,” declared Mr Brown.

“I don’t think they have any answer on the borders either, because if you want a separate migration policy in Scotland...you can’t have an open border any more, you have to have a border where people are checked as they go from Scotland into England,” he added.

James Dornan for the SNP said the former Labour leader’s conversion to greater powers for Holyrood was welcome and that Mr Brown, as the “architect” of the so-called vow, was now admitting that pledge hadn't gone “nearly far enough”.

He said: “This is an astonishing development that shows how the very real threat of Scotland being dragged out of the EU against our will is causing people to fundamentally rethink firmly held views on the constitution.

“Gordon Brown was behind Labour’s decision to block the transfer of employment protections, of more revenues and of greater responsibility to the parliament, so this conversion is very welcome.”

The MSP added: “We agree that doing nothing is not an option but the suggestion of a federal UK is very unlikely to win support across England.

“Keeping Scotland in Europe is the Scottish Government’s starting point and the First Minister is absolutely right to keep all options on the table to achieve that, including a second independence referendum.”