On the one hand it will be seen as a measure of just how unpopular Gordon Brown's government has become. If Labour can't hold on to such a traditionally Labour stronghold in his own back yard Mr Brown's days as PM are suerly numbered.
On the other hand the by election will also be an important measure of how well Alex Salmond's SNP government is fairing. Making a mark in places like Glasgow is going to be imperative if Mr Salmond hopes to form a majority government in 2011 and be equally important in any independence referendum.
It is not surprising, therefore, that the battle for Glasgow East is going to be passionate, hard fought and at times even dirty. Having said this I have been pleasantly surprised so far having read the Scottish blogs and newspaper comments sites. So far there has been no evidence of the foul sectarianism that has blighted the city's politics in the past.
I was bitterly disappointed, on turning to the Welsh blogs, to find that one of our own MPs, Paul Flynn, has started throwing the sectarian dirt re Glasgow East:
But there is deep reassuring loyalty from the ‘Labour until I die’ folk of Glasgow. There are more of them in this constituency than anywhere else in Scotland. Religion may be a factor with a Baptist SNP candidate and a Labour one with an Irish name.