THE pro-Union arguments used by Better Together to persuade Scots to remain part of the UK should be used as a blueprint for Europhile politicians if Britons have the chance to vote in a referendum on European Union membership, Lord Robertson has said.

The former Labour Cabinet minister, now known as Lord Robertson of Port Ellen, warned that leaving the EU would be disastrous for Britain.

He said all the arguments deployed in the Better Together campaign to retain the Union with Scotland applied to the EU and should be reformulated for a debate on EU membership.

If the arguments were put cogently and a referendum on EU membership was held, said Lord Robertson, the British people would "reach the same conclusion as the Scots" and vote to retain the existing relationship with the EU.

His comments came during a debate in the House of Lords last night.

Prime Minister David Cameron has promised UK voters an "in-out" referendum on the EU if the Conservatives form a majority government after next year's General Election.

Labour's spokesman on Europe, Lord Liddle, said: "Britain is sleepwalking towards exit. The blame rests fairly and squarely on the shoulders of the Prime Minister. I've come to the sad and rather depressing conclusion that our membership of the EU is no longer safe in David Cameron's hands."

Lord Liddle said the Government's European policy had "hardened beyond recognition" since the summer and accused Mr Cameron of being prepared to say anything to win over potential Ukip voters.

Ukip now has two MPs at Westminster as a result of by-elections sparked when former Conservative MPs defected.

Lord Liddle warned that quitting the EU would leave Britain isolated, with "untold consequences" for jobs.

Tory former foreign office minister Lord Howell of Guildford insisted there was an appetite for reform across the EU and denied that Britain was a lone voice for change.

He said treaty change was inevitable.