If further proof is required that the political marriage between Tony Blair and Gordon Brown is bound to end in divorce, one need only look at the identity of the self-appointed marriage guidance counsellor.

John Prescott, the Deputy Prime Minister, has spent the past two years as the would-be peacemaker between the Prime Minister and Chancellor. Given Mr Prescott’s lamentable track record, it is little wonder that relations between the two most important political figures in the land are now at breaking point.

However inept a minister he may be, the Deputy Prime Minister remains deeply popular within the Labour Party. Were he to pronounce one way or another - for either Brown or Blair - his views would carry enormous weight within the party. That is why both Mr Blair and Mr Brown, who might otherwise dismiss him as a buffoon, have to listen to him when he speaks.

Certainly, ever since his election as Deputy Leader of the Labour Party in 1994, John Prescott has seen his main role as protecting his leader, Tony Blair. The two men could not be more different: Blair with the smooth charm of a privileged upbringing, at ease with the profits of capitalism; Prescott rough and chippy, with a hatred of business and the ‘beautiful people’ (as he sneeringly calls them) brought to the fore under New Labour.

It is precisely because of that difference that Mr Blair was so keen to have Mr Prescott as his deputy - a man steeped in Labour traditions, who could be relied on to give the newcomer leader the backing he would need in an often hostile party. Sometimes that has meant persuading recalcitrant Labour MPs to support the government in Commons votes. More often than not, of late, it has meant dealing with the latest stirring of the ‘Teebeegeebees’, the name given by insiders to the rows between Mr Blair and Mr Brown after their TB/GB initials.

So when, in the autumn of 2003, rumours were circulating across Westminster that the Teebeegeebees were raging once more, it was nothing new for Mr Prescott to try to calm the waves. On 6th November 2003, he hosted a dinner at his Admiralty House residence for the Prime Minister and Chancellor, his aim being to knock sense into both of them and to point out that the more they rowed, the more damage was done to the government and thus, in the long run, to each of them.

That dinner has long been public knowledge. According to an explosive new book, however, the Prime Minister told the Chancellor at the dinner that he would resign before the next election but that he needed Mr Brown's help and support 'to get through the next year'. The book claims that the proposed handover was then discussed at a series of further meetings, including one attended by both Peter Mandelson and Mr Prescott.

My information suggests that, far from committing himself to resigning, Mr Blair demanded that Mr Brown help him regain his public standing after an abysmal year in the aftermath of the Kelly affair and the continuing deterioration in Iraq.
And that if he did salvage his reputation, he said he could then resign honourably and hand over the crown from a position of strength.

Whatever the truth, the thing we know for certain is that there was one ever-present figure in discussions between the two men: John Prescott. Yet just one glance at the Deputy Prime Minister’s political track record reveals that everything Mr Prescott touches turn to dust.

To look at his lack of achievement is to wonder why on earth anyone would imagine John Prescott is capable of Cabinet office, let alone skilful enough to negotiate a settlement between two such powerful figures as the Prime Minister and the Chancellor.

Take his most recent cock-up, the much-vaunted plan for an elected assembly in the North-East. Mr Prescott pushed it onto the government’s agenda, pushed for the referendum and then pushed for a ‘yes’ vote. The result: in the November referendum, 78 per cent of voters told him where he could put his assembly. Every single one of the 23 council areas affected voted against the plan. It was an intensely personal humiliation for Mr Prescott. And at a cost of over £10 million to the taxpayer.

Mr Prescott’s list of failures is quite simply awesome. Any other minister would long ago have been sacked with such a record.

Local government finance - the council tax - has become steadily more unfair and steadily more complicated under his command. Even the Labour dominated Commons select committee on Transport, Local Government and the Regions described his performance as 'woeful'.

Housing policy has entered the realms of the absurd, blowing from one contradictory extreme to another - restricting right-to-buy, moving council tenants out of local authority control and reigniting council house building.

As for transport: as anyone who has to travel knows, Two Jags’s record was so appalling that even Mr Blair despaired, and removed transport from his grasp. His sole contribution seemed to be a bus lane on the M4 which brought the motorway to a virtual standstill.

In policy matters, he is simply incompetent.

In regard to Mr Blair and Mr Brown’s squabbles, however, he is dealing with matters in which he is intimately steeped - the Labour Party itself. But that does not make him any more capable of giving out the correct advice.

Mr Prescott’s first public intervention in the affair, in May last year came in a very carefully worded interview with The Times - unusually for a man whose words are usually splayed as if being fired from an out of alignment machine gun - about how the 'plates' were 'shifting' in politics.

He was clearly referring to the Brown/Blair relationship and its possible outcome. And since Mr Prescott knows the Labour Party backwards, and can sense its nuances, his words had a seismic effect.

What few could understand, however, was why he would be so open about the crisis. The answer lies in Mr Prescott’s personality.

In researching my biography of David Blunkett, I came across numerous examples of John Prescott attempting to stir the pot. It is as if he cannot bear the way he is regarded - as a politician whose role is entirely symbolic, a relic of Old Labour. And so, every so often, he cannot resist making a splash, drawing attention to himself and reminding people that he is a major Labour Party player.

Indeed, his lack of judgement revealed itself in his reaction to my book. After a week of wall-to-wall coverage of my revelations, by the following week interest had focussed on Mr Blunkett himself rather than my book. And then Mr Prescott waded in. Speaking on the Today programme in an interview about inner city policy, he responded to a perfectly obvious question about David Blunkett's comments not with a calm, prepared line but with a full-on rant about me, because the whole affair "has come about because of an element of personal arrogance, and a very large measure of personal greed and book sales of the author Stephen Pollard."

Cue intense media interest in an otherwise dormant story: how do you feel about being called greedy by John Prescott? Etc.

If there is one man who should not be given the job of dousing out a fire, it is John Prescott. However one looks at it, Mr Prescott’s influence in the Teebeegeebees, as in so many other areas, has been baleful. The Prime Minister and his Chancellor are at each others' throats as never before. Some peacemaker!

(There was a very embarrassing spelling mistake in an earlier version of this posting.)