Did she jump before she was pushed? That is the big question in Scotland this morning after the surprise resignation of Wendy Alexander yesterday.

Following what must rank as one of the most disastrous leaderships of any party, dogged by a donations scandal, capricious policy U-turns and a worrying absence of judgment, she finally caved in to pressure in the early hours of Saturday.

Speculation is rife, of course, that she was nudged out in the end by Gordon Brown, her one-time mentor and her friend, whose own political fortunes were being adversely affected by the growing liability north of the border.

When Alexander started being mentioned regularly in stories of Brown’s failing premiership, patience for her in the party wore thin. He is said to have phoned her on Friday and told her at least to think about things.

However, she has distanced herself from London since becoming leader and is famously stubborn. Rather like Brown, she has always been convinced she had a mission and, despite plenty of evidence to the contrary, insisted she was not only good for Scottish Labour but good for Scotland.

Uncharitable souls may have said she was motivated more by ambition than conviction but, whatever the truth, she managed to survive her scandals when much bigger political beasts (Peter Hain) and much better operators (David McLetchie) were forced out by theirs.

Until this weekend. Mired in controversy for most of the 10 months she has led Labour, things came to a head on Thursday with her suspension by the standards committee.

The suspension would have depended upon a vote by the parliament, now in recess until September, and perhaps the thought of this cloud hovering over her was the final straw for Alexander.

Adding to her woes was the sudden resignation of Glasgow East MP David Marshall for health reasons. His seat, in Labour’s heartland, is relatively safe but the prospect of a strong showing by the SNP and by-election humiliation on top of everything else might have been another deciding factor.

More likely, though, Alexander has taken the advice of her family. Her husband, the academic Brian Ashcroft, and her parents are believed to have urged her to stand down for some time. One thing is likely: her decision will not have been greatly influenced by conscience because her’s was not troubled.

All along she has denied any intentional wrongdoing, either in accepting cheques from offshore businessmen or forgetting to register campaign “gifts”. She has also sought to lessen her misdemeanours by maintaining that the sums involved, all under £1,000, were not large enough to warrant her resignation.

Neither of these was ever a satisfactory defence. The rules are perfectly clear. They were drawn up by the Labour party and, as its brainiest member (allegedly), she would have understood them.