FORMER Deputy First Minister and Liberal Democrat peer Lord Stephen has effectively slapped down party colleagues Michael Moore and Nick Clegg by saying Westminster politicians should keep out of the referendum debate.

He was critical of Downing Street spin doctors for presenting the 18-month deadline on a legally-binding referendum as a threat, saying the plan was logical but it should not come from Westminster.

"It's best that the campaign is run from Scotland and that Scottish politicians in Edinburgh and the Scottish Parliament take the lead role in the campaign," he said.

"People like David Cameron, and indeed Nick Clegg and Ed Miliband, becoming too central in the campaign will just provide ammunition to Alex Salmond -

"Any opportunity that Alex Salmond gets to turn this into a party-political confrontation between Scotland and Westminster he will try to grab with both hands."

Lord Stephen thought offering power in the Scotland Bill to Holyrood to organise a referendum was right but added: "I think the way it was announced by the UK Prime Minister and the spin talking about 'this has to happen in 18 months' plays into Alex Salmond's hands."

The SNP pointed out another LibDem former deputy first minister had said "a politically sensible" UK Government would not set a referendum."

SNP MSP Linda Fabiani, who convened the Scotland Bill Committee, said: "Labour and the LibDems must be squirming as they watch their leaders sign up with an unpopular Tory party to campaign against the ambitions of the people of Scotland - Lord Stephen and Tavish Scott recognise the need for the campaign and the referendum to be made in Scotland."