By Nick Assinder BBC News Online political correspondent

The revelation that John Prescott has diabetes has inevitably led to renewed speculation over his future.

There have been persistent rumours that the deputy prime minister has decided to stand down as MP for Hull before the next general election.

Under doctor's orders

He long ago gave up any ambition of leading the Labour Party.

And there have been claims that he has become disillusioned with the New Labour government under Tony Blair.

He has emphatically denied all these suggestions and there is ample evidence that he means what he says.

Doctor's orders

As a result, some have suggested he is waiting until nearer the time to announce his retirement, allowing the Labour Party greater influence over his successor.

But, it has to be said, there has been precious little up to now to substantiate any of this, but plenty to suggest Mr Prescott fully intends to stay.

Doctor's orders, of course, could finally change all that.

If he was looking for an excuse to retire - over and above the fact that he shortly hits 65 - this could well be it.

The deputy prime minister is a ferocious worker and his lifestyle seems designed not to help him deal with his condition.

He needs to eat less, and different food and he has been ordered to get more sleep and take regular medication.

Fed up

He has already eased off the throttle a little, but it is not in his nature to take things easy.

And if he has been under doctor's orders since shortly after the 1997 election, there is little sign it has had any dramatic effect on him.

If he does intend to retire, what he does not want is a rash of stories that he is quitting because he is fed up with New Labour or has become disillusioned.

Claiming ill health would be a perfectly reasonable and uncontroversial explanation for his retirement.

Whatever happens - the thought of Lord Prescott of Hull in the Upper House is something everyone could rejoice in.