Tony Blair shrugged off a catalogue of crises engulfing his Government, saying: "It's just the way it is."

He insisted he would get on with his job after woes over Deputy Prime Minister John Prescott's affair with a civil service secretary, the row over foreign prisoners and Health Secretary Patricia Hewitt's heckling by nurses were joined by controversies over crime figures and class sizes.

Mr Blair, on a campaigning visit in London before next week's local elections, said of the events of on Wednesday which saw three Cabinet ministers on the ropes: "It is not a great day."

Neither Mr Prescott nor Ms Hewitt had offered to resign, he said. And he defended Home Secretary Charles Clarke over the Whitehall chaos that saw more than 1,000 foreign nationals released from prison without being considered for deportation as they should have been.

Earlier, Work and Pensions Secretary John Hutton denied the Government was in "meltdown".

The Prime Minister used an interview with the BBC to clear Mr Prescott of any breaches of the ministerial code over his affair with his diary manager Tracey Temple.

Tory backbenchers Andrew Robathan and Derek Conway queried Downing Street's insistence that the affair was a "private matter".

Mr Conway tabled parliamentary questions and Mr Robathan raised the issue of whether Mr Prescott had abused his position of authority or his official residence by allegedly entertaining Ms Temple there.

But Mr Blair said simply: "That's a personal matter and I'm not going to say any more about it."

He strongly defended Health Secretary Patricia Hewitt, after her torrid week at the hands of nurses and health workers over job cuts in the NHS.

Asked whether she had offered to resign, he said: "Certainly not - and nor should she."

He added: "I don't know anybody who seriously disputes these reforms are necessary to put the health service on a sustainable basis with all the investment that's going on, and she is absolutely right on carry on doing that."

On the deportations crisis, Mr Blair said that Mr Clarke should be allowed to get on with the job. He said: "To be fair to him he is actually sorting it out now, I think he should get on and sort it out."

Mr Blair said: "In this business, in the media culture that we have today, where there's no problem that isn't a crisis, no difficulty that isn't a catastrophe. You can decide this according to whatever is the latest scandal rolling around the news, or you can say this is what it's about, this happened as a result of a decision taken by Government and that's why we are in politics and that's just the way it is."

Tory leader David Cameron said: "It is a very, very dark day for the Government. The Prime Minister has got to get a grip."