Scottish Labour leader Kezia Dugdale will today call for a UK-wide constitutional convention to "save" Britain.

In a speech in London, Ms Dugdale will say that if the Prime Minister Theresa May does not establish such a group then Labour should.

And she will accuse the Conservatives of putting the Union at risk.

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Former Labour prime minister Gordon Brown has called for a constitutional convention to consider the make-up of the UK.

In recent weeks he has suggested that it could also look at giving Scotland, Wales, Northern Ireland and the English regions control over areas taken back from Brussels, such as agriculture and fisheries, after Brexit.

Ms Dugdale will write to Mrs May to call on the Government to establish a convention, which Labour sources said would examine the “erratic” nature of devolution across the UK in recent years.

In her speech at the IPPR think tank, Miss Dugdale is expected to say: “The time has come for the rest of the UK to follow where Scotland led in the 1980s and 1990s and establish a People’s Constitutional Convention to re-establish the UK for a new age.

“The convention should bring together groups to deliberate on the future of our country and propose a way forward that strengthens the UK and establishes a new political settlement for the whole of our country.

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“This is a Convention that the Government should convene, and I have written to Theresa May today outlining Scottish Labour’s desire to see this happen. However, if the Government is not willing, as Gordon Brown has said, the opposition should convene a Convention.

“Some may say this is unrealistic, but it would follow the model of the Scottish Constitutional Convention which, without Government support, established the basis for the settlement that delivered a Scottish Parliament in 1999.

“It would also – for the first time – provide a coherent approach to answering the question of how our country is best governed.

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“While devolution has been positive for Scotland, Wales and Northern Ireland, we have to acknowledge that progress has been erratic and while there has been significant progress in some parts of the UK, other parts have been left behind.”