THERE are times in politics when the momentum which builds up against a senior figure is simply irresistible - just ask Peter Mandelson.

Whether David Blunkett has broken the rules governing his position as Home Secretary will be decided by Sir Alan Budd's inquiry next week.

But the drip, drip, drip effect has already done much to erode Mr Blunkett's credibility as the man in charge of law and order - right and wrong - in Britain.

We do not support all of Mr Blunkett's measures as Home Secretary. We do not like the arrogance of someone who believes that he can simply erase all questions about his conduct by repaying the cost of the rail ticket he passed on to his lover.

But we do respect him as a remarkable man who has risen to one of the top jobs in the Government despite being unable to see. His achievements are undeniably brilliant; his determination awe-inspiring.

That will not save Mr Blunkett, however, if the Budd inquiry concludes that the Home Secretary played any part in fast-tracking a visa application by his lover's nanny.

And even if he is officially exhonerated, Mr Blunkett will be damaged goods thanks to a messy sex scandal, which has come as an early Christmas present to the media.

Mr Mandelson was eventually cleared of wrong-doing over the Hinduja passport affair.

But it did not prevent him from being forced out of office by newspaper editors desperate to claim his scalp for a second time.

Mr Blunkett has not made as many enemies as Mr Mandelson, but he is going to need all the friends he can get to save his skin.