There is another possible development which might alter the SNP's focus. Labour leaders at Holyrood are waiting for Jack McConnell's decision on when he intends to stand down as the MSP for Motherwell and Wishaw so he can go to Malawi as the UK's High Commissioner.The former first minister has said he won't make a decision until he gets confirmation of his appointment from the Foreign Office.If the Foreign Office endorses his appointment, his contract should come to him soon, which means he could stand down in the next couple of months, forcing a by-election for Holyrood on the same day as the Glenrothes poll.

Mr Woodward has been tipped to take over as Defence Secretary — one of the plum Cabinet jobs. It is a proposed move that has caused dismay and resentment in some sections of the Labour Party, since Mr Woodward has been in their ranks for less than a decade. He defected from the Tories as an MP in 1999 and was given a safe Labour seat two years later. And the current Defence Secretary, former NIO Minister Des Browne, is being weighed up for a return to Belfast as the head of the new department.