AN ACADEMIC is demanding a formal apology after he was shouted down by an MSP while he gave evidence to a Holyrood committee.

Adam Tomkins, a professor of public law at Glasgow University, said he would write to SNP backbencher Willie Coffey following heated exchanges at a European committee meeting yesterday.

He said he would also complain to the committee convener, the SNP's Christina McKelvie, who cut off his comments in an effort to end the row.

Professor Tomkins, who advised the Scottish Conservatives on their recently-unveiled devolution proposals, told the committee the Scottish Government's independence White Paper was wrong to claim that a go-it-alone Scotland would be entitled to use UK overseas properties for some diplomatic postings.

Mr Coffey said he was "a wee bit disappointed by the tone of some of Professor Tomkins' contributions".

He began shouting across the room when the academic attempted to explain his point.

Both were silenced by Ms McKelvie.

Opposition MSPs complained that the professor's evidence should not have been cut off but Ms McKelvie said: "I can if it's becoming contentious."

Professor Tomkins said later: "I'm going to write to Mr Coffey because it was disrespectful."