David Maddox: Why are the Nationalists so keen to defend the Speaker?

Tomorrow (Monday) is a defining day for the future of the embattled Speaker Michael Martin (pictured right) as he makes as statement on expenses to MPs and faces his growing number of critics.

But one corner where he does have some friends appears to be among his historic die hard opponents in the SNP

This blog has noted before how SNP's Westminster leader Angus Robertson gave his backing to the Speaker Martin at another time of beleaguerment.

And this week his colleague Glasgow East hero John Mason (pictured below left) has been saying the same thing as the same thing on Good Morning Scotland and on the Politics Show today.

It is surprising considering that there is little love lost between Scottish Labour (especially of its West of Scotland variety) and the Nationalists. It is not even as though Mr Mason, unlike Mr Robertson, has had his snout in the trough.

Both Mason and Robertson at different times have pointed to the snobbery against the working class Glaswegian Speaker, but also paid tribute to his fairness.

"He always calls me to speak when I want to," said Mr Mason today, echoing the words of his Westminster leader a few months ago.

But interestingly of the Scottish contingent only the Lib Dems have taken a pop. the sole Scottish Conservative David Mundell has also supported Speaker Martin.

All of which gives the impression that possibly there is concern within the Scottish ranks cross parties that their opportunities may be more limited if he is replaced by a new Speaker from south of the border.