By BBC News Online's political correspondent Nick Assinder

Tony Blair has taken a significant political gamble by declaring he accepts full responsibility for sorting out the creaking NHS.

At the end of one of the government's most difficult weeks he attempted to end the row over the funding of the health service which has severely damaged his standing.

He was asked what his message was to Jane Skeet whose mother, Mavis, has had a cancer operation cancelled four times because of bed shortages and cannot now be saved.

"My message is that I accept the responsibility to make sure that the situation that occurred in respect of her mother does not recur.

"I accept that responsibility. I am trying to put it right," he said.

He also accepted that there were problems with the service, but pledged he would put them right.

His comments echoed the "trust me" message he gave voters in 1997 after it was revealed he had accepted a £1m donation from Formula One boss Bernie Ecclestone as the government was planning to ban tobacco advertising at motor racing events.

He insisted much of the problem was a result of the previous Tory government's policies.

And he said it would take at least five years to put things right.

Hugely difficult task

But he knows he has only a year before the next general election to make a significant improvement, or face the anger of voters who will feel they have been let down.

He put the health service at the centre of his pre-election manifesto and the current crisis has handed the Tories a powerful political weapon.

They have seized the opportunity and been harrying the government for the past week over its alleged broken election promises.

But, in an attempt to damp down the row, Mr Blair has set himself a hugely difficult task.

Voters will expect to see real improvements in the service before the next election.

That will be hard enough to achieve, but another bad winter similar to this year's will make it even more difficult.

Pledges hard to meet

Mr Blair also refused to attack Labour peer Lord Winston who sharpened the crisis with a stinging attack on the government's record on the NHS.

The prime minister and his spin doctor Alastair Campbell faced charges of bullying when Lord Winston qualified his comments following a phone call from Mr Campbell.

There were fears that the government was about to engage in an exercise to rubbish Lord Winston rather than address his criticisms.

But Mr Blair pointedly avoided making any direct attacks on Lord Winston.

He rejected the peer's suggestion that more cash for the NHS could only come from taxation or private insurance.

But, in doing so, he also suggested that more resources were dependent on ensuring the economy kept growing.

By implication, any economic downturn will inevitably see a reduction in cash to the service.

He has now made pledges on the health service that will be difficult to meet but which voters will expect him to fulfil.

And his claims that it will take years to put things right will not help if clear improvements are not seen by the time of the next general election.