Alex Salmond has signalled a return to frontline politics as he insisted the British establishment has never been more fractured.

The former first minister said he was waiting for the starting gun of a second independence referendum before returning to the fray.

He argued the SNP's political opponents in the UK had never been weaker, while Britain's isolation in Europe was "truly meaningful" for the next Yes campaign.

But a Scottish Conservative spokesman accused him of "ignoring the inconvenient facts that a majority of the population in Scotland still want to be part of the United Kingdom, and there has been no shift in that position for some time".

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Speaking at an SNP branch meeting in Edinburgh's upmarket Morningside area, Mr Salmond insisted the case for independence would be "virtually unanswerable" if UK ministers pushed ahead with their flagship Brexit Bill.

The legislation was overwhelmingly rejected by MSPs at Holyrood earlier this week amid fears it represented a "power grab" that undermined devolution.

Mr Salmond said he would return to the political fray as soon as a second referendum was called – jokingly dubbing his pledge "the declaration of Morningside".

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He said: "The declaration of Morningside is this. I have got no immediate political ambitions. I'm very happy doing what I'm doing at the present moment.

"I'm happy writing articles, doing video blogs, I'm happy doing TV programmes and all the rest of it – I'm happy doing the stage shows.

"But the day and the hour that Nicola [Sturgeon] fires that starting gun, I will be on my marks and ready to go for the Yes campaign."

He said the case for independence would be boosted if the Scottish Parliament's Brexit vote was ignored.

He added: "I think it would leave it in a fundamentally strong position, with the ball in the penalty spot and waiting for Nicola Sturgeon to kick it into the net."

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Mr Salmond lost his seat to the Scottish Tories in last year's General Election following a swing of 20 per cent against him.

He went on to front a sell-out Edinburgh Fringe show, Alex Salmond Unleashed, before launching his own chat show on Russian TV channel RT in November.

But the programme has been heavily criticised amid claims it legitimises RT's propaganda output, with Nicola Sturgeon revealing she would have advised against the move "had I been asked".