By Nick Assinder BBC News Online political correspondent

John Prescott is without doubt one of the most experienced trades unionists on the government's front bench.

But you wouldn't ever want to negotiate with him.

If you can work out what he has said you still can't be sure what he meant.

Davis said government interfered

And he was on prime form in the Commons when he updated MPs on the firefighters' dispute.

He came to the chamber facing accusations from Tory shadow David Davis and others that he had interfered in the dispute and, as a result, ensured an early deal was blocked.

There was the continuing question mark over whether the government had pre-empted an independent inquiry by insisting there would be no more money for pay rises.

No strike

There may even have been a lingering suspicion with some that he was quietly on the side of the workers.

He was crystal clear over some of the issues. The dispute was indefensible, there would be no more money and the FBU should cooperate with the inquiry.

He also flatly denied interfering in the dispute.

On other issues there was, to say the least, some ambiguity.

Glowing with union pride

But I THINK he accepted that ordinary firefighters across the country wanted the dispute. Some in government have suggested they are being manipulated by their leaders.

I'm also fairly certain he ruled out any move to introduce a no strike clause in any eventual deal.

Conciliatory tone

But I'm not at all sure what he meant when he said the firefighters' concerns had "registered" with the government. Probably nothing.

He also veered between apparent anger at the firefighters and a more conciliatory tone.

When reminded of his own union roots by old comrade and flat-sharer Dennis Skinner he positively glowed with pride before suggesting that, in his day, they had always acted reasonably, while this lot were being irresponsible and dangerous.

Next he was talking about social justice for the workers and figuratively putting his arm around the shoulder of FBU leader Andrew Gilchrist, urging "Andy" to play the inquiry game.

It was all a bit confusing. But then that will probably delight the prime minister and others who know they can never be held to account for anything the deputy prime minister appears to say.