By Nick Assinder
Political Correspondent, BBC News website
Mr Prescott has appealed for privacy
John Prescott, backed by the prime minister, insists his sexual antics with his diary secretary are a purely private matter, and he has asked the press to back off.
He must know that is a forlorn hope and that his private life is now going to be the subject of continuing scrutiny, not to mention humour. The involvement of Max Clifford probably ensures that.
And, as ever, it is the drip, drip of claims and counter claims - particularly if combined with lurid details of sexual behaviour - that can quickly erode a politician's position and authority.
Becoming a nationwide figure of fun can also do as much damage, if not more, than the original "offence".
Former Tory politicians, most obviously David Mellor, discovered the truth of that. And, of course, Mr Prescott made much of the Tories' woes over sleaze - a word that can probably never again pass his lips in relation to other politicians without the allegation of hypocrisy being thrown at him.
That is one obvious problem for Tony Blair, who is already being battered by the crisis over freed foreign criminals and demands he sack home secretary Charles Clarke.
The government has started attracting allegations of sleaze and the last thing the prime minister needs now is something like this, just days before the local elections, to add to that impression.
Then there is the continuing question over whether Mr Prescott's behaviour really is a purely private matter and has not impacted on his public life and ministerial job.
For a start there are the questions about his use of his ministerial facilities while conducting his affair.
Standards watchdog, Sir Alastair Graham, has raised the prospect that Mr Prescott may have breached the ministerial code.
That is a line of attack that has already been pursued by Tories in the Commons and will continue right through to the local elections on Thursday.
The deputy prime minister was in the forefront of that campaign, attempting to minimise the losses party bosses were already braced for.
Now he will not only find it near impossible to continue campaigning, but he is being seen as actually adding to the party's troubles.
But, despite all this, the prime minister does not want to lose his deputy, who he uses as a symbolic link with old Labour and the trades unions.
Time and again it has been Mr Prescott who has kept rebellious unions and old Labour MPs on board the New Labour train.
And he has been there to give the party an appeal beyond the middle England voters Mr Blair has attracted to the New Labour.
Mr Prescott is also the man responsible for easing the transition of power from Tony Blair to Gordon Brown.
Transport secretary Alastair Darling has again insisted there is no agreed plan for that handover between the two men themselves - another indication of how central Mr Prescott may have been to that development.
Yet there must now be a question mark over whether Mr Prescott can, or will wish, to stay on.
For the time being he is insisting he has no intention of resigning and, just like Home Secretary Charles Clarke, will battle through.
But all eyes will now turn to the cabinet re-shuffle, expected to be carried out by the prime minister shortly after the local elections.
That event is already being described as a "re-launch" of the struggling government and, if that is indeed the prime minister's intention, he may well want to clear the decks of the problems that have beset him over recent weeks and months.
And just how wide-ranging that re-shuffle is probably hangs on just how badly Labour does in those crucial polls.