By Nick Assinder BBC News Online political correspondent

Galloway was a regular visitor to Baghdad

The rebellious left-winger has been a persistent thorn in the side of New Labour. And it is likely he will continue to be so.

But he overstepped the mark as far as Tony Blair was concerned when he attacked him over the Iraq war.

Plenty of others made similar attacks, but Mr Galloway went further than most and, in effect, handed the Labour leadership the reason, some would say, it had been looking for to expel him.

Until then, he had been tolerated by the Labour leadership which probably felt that expelling him would be more trouble than it was worth.

Got worse

Not to have taken action this time might have been seen as a sign of weakness.

But the danger for the prime minister now is that he may have created a martyr.

Feelings against the war have probably hardened since Mr Galloway made his remarks and since he was suspended.

If he stands as an independent against a Labour candidate there are many who predict he will very likely win.

And the party's past record in expelling people like Falkirk's Denis Canavan and Ken Livingstone do not bode well for Mr Blair.

Focal point

The action also opens up another can of worms. Will Labour now have to take similar action against other war rebels such as Glenda Jackson and Bob Marshall Andrews.

No one is expecting that. These people, along with scores of others, opposed the war and made stinging attacks on Tony Blair, but Mr Galloway went much further than them.

What will almost certainly now happen is that Mr Galloway will pursue a campaign against the Labour leadership.

The rebels may well rally behind him and he could provide a powerful, eloquent and persuasive focal point for that campaign.

Mr Galloway was never going to go quietly and he has already shown just how troublesome he may be in the future.

It remains to be seen whether Tony Blair may end up wondering whether it would have been better to leave him languishing - albeit loudly - on the backbenches.