Gordon Brown is to return to politics to lead a commission tasked with settling "the future of the union", Labour leader Sir Keir Starmer has said. 

The former Prime Minister will re-examine the devolution settlement and devise a 'second phase' of the transfer of powers from Westminster to Holyrood.

However, any plans drawn up would be dependent on Labour forming the nextUK Government. 

The move has been backed by the Lib Dems, who said Mr Brown brings "heft" to the campaign to stand up for Scotland’s place in the UK.

The constitution commission was anounced last year bid to see off support for the SNP and calls for a second independence referendum, with Mr Brown mooted as an advisor. 

But it has now been confirmed that the Labour grandee will return to politics to take the reigns as its leader.

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Mr Brown, who was in Number 10 from 2007 to 2010, is one of the loudest voices in favour of the union, having a prominent place in the final days of the 2014 independence referendum campaign.

HeraldScotland:

Sir Keir Starmer

During his speech to the Labour conference, Sir Keir said: “As Gordon Brown said recently ‘when a Welsh or a Scottish woman gives blood…she doesn’t demand an assurance it must not go to an English patient’.

“I am delighted that Gordon will lead our commission to settle the future of the union.

“And I know Gordon believes that if you look past the Tories’ pathetic attempts to divide us in a culture war you can glimpse a tolerant, progressive nation of which we can be proud.

“I believe that our diversity is one of the things that makes this country great.”

The Liberal Democrats have said they are open to working with Mr Brown on the Labour Party commission.

After the speech, Lib Dem Scottish affairs spokeswoman Wendy Chamberlain said her party would work with Mr Brown on the commission.

HeraldScotland:

Wendy Chamberlin

“Gordon Brown brings heft to the campaign to stand up for Scotland’s place in the UK and make the case for a reformed UK against the damage caused by the twin nationalisms presented by the Conservatives and the SNP,” she said.

READ MORE: Gordon Brown warns next UK general election could pit 'Scotland versus Britain'

“Liberal Democrats have long campaigned for reforming the whole of the UK with federalism, voting reform and an elected second chamber.

“If Labour are moving it that direction, we’d be happy to discuss that agenda with the former prime minister.”