SPECULATION is mounting at Westminster that David Cameron's final appointment to his new-look majority Government, for the post of Advocate General for Scotland, will be Richard Keen QC, currently Chairman of the Scottish Conservatives.

An announcement as to who will succeed Liberal Democrat peer Lord Wallace of Tankerness, who held the role of the UK Government's senior Scottish law officer during the Coalition years, is due in the next 48 hours, Whitehall sources said.

One of the main tasks for the new Advocate General will be to take the proposed Scotland Bill, giving Holyrood more powers, through the second chamber.

Mr Keen, 61, is one of Scotland's most respected lawyers. He was a former Dean of the Faculty of Advocates before he was appointed to head the Management Board of the Scottish Tories.

In an illustrious career, Mr Keen, described as a "brilliant lawyer", has worked on the Piper Alpha case, led the defence of Lamin Fhimah in the Lockerbie bombing trial and in 2013 was taken on to represent Andy Coulson, David Cameron's former director of communications, who is facing perjury charges in Scotland.

Earlier this year, he was dragged into a row over illegal proxy donors, after indicating he once gave £10,000 to the party under his wife's name. However, the Scottish Tories later made clear the money had come directly from his wife.

Dubbed "the Rottweiler" for his courtroom ferocity, and reputedly the highest paid member of the Scottish Bar, Mr Keen was the personal choice of Scottish leader Ruth Davidson to become Tory Chairman, a decision endorsed by the Prime Minister.

Second only to Ms Davidson, his role, as well as chairing the Scottish party's management board, is to develop political strategy, liaise with the UK Conservatives, and help improve election operations.

Married with two children, Mr Keen is a member of the Bar not only in Scotland but also in England and Wales. While he lives in Edinburgh, he also practises in London.