Soft Scot who impressed Blair

Alistair Darling, who has replaced Stephen Byers following his resignation yesterday, lists transport as his chief "special interest".

As Work and Pensions Secretary, he has proved exactly the sort of low-profile minister Tony Blair craves in the post of Secretary of State for Transport after Mr Byers.

The Prime Minister has been impressed by how the softly-spoken lawyer has skilfully avoided the fall-out from the pensions row in recent months.

Mr Darling, MP for Edinburgh Central since 1987, is inexorably linked to Gordon Brown - once described as simply the Chancellor's "mouthpiece".

He was the youngest member of Mr Blair's Cabinet when he was appointed Chief Secretary to the Treasury in 1997 aged 43.

Like Mr Byers, Mr Darling has a left-wing past as an anti-nuclear, anti-devolutionist but swiftly moved into the party mainstream as it underwent the transformation to New Labour.

Now 48, his polished Commons performances have won respect from MPs of all colours.

Educated at Loretto School and Aberdeen University, he is married with one son and one daughter.

One possible fly in the ointment is the prospect that he could lose his Edinburgh seat following the Boundary Commission for Scotland's decision to cut one of the city's constituencies in a review of the number of Scots MPs.