By Nick Assinder BBC News Online political correspondent

For once it has not been necessary to read between the lines to spot the split between the prime minister and some of his ministers over a key policy.

It is patently obvious from their language that Work Secretary Alistair Darling and Deputy Prime Minister John Prescott are deeply unimpressed by the idea of cutting child benefit to the mothers of truanting yobs.

Darling seemed unimpressed

But it is equally plain that the prime minister is hugely attracted to the idea and is not about to abandon it.

Along with the plan to put police officers in troublespot schools, it is seen by Mr Blair as an effective way of tackling street crime.

Mr Prescott admitted he knew nothing about it until he read his Sunday newspapers, and then his reaction appeared decidedly lukewarm.

Doesn't like it

And it looks like Mr Darling was unaware just how much the prime minister was involved in promoting the proposal.

But, whether he was fully aware of the priority being given to the plan or not, he obviously does not like it either.

Both men have refused to offer their personal support for the suggestion, insisting it is just one of many being discussed by the government's street-crime action group.

It is also being suggested that Chancellor Gordon Brown is opposed to the suggestion.

But Tony Blair could not be more enthusiastic. His official spokesman insisted the prime minister was "totally unapologetic" about the proposal and said if the attempt in some quarters was to shoot it down "then think again".

The prime minister, he said, never shrank from taking difficult or controversial decisions.

Knee jerk

What many suspect is that, with the focus now on the rising level of street crime and with local elections just three days away, the prime minister is eager to be seen taking tough action.

Blair set September deadline

His pledge last week to have got the problem "under control" by September has also put him firmly on the spot.

But his critics - which include the opposition parties, welfare groups and many of his own backbenchers - believe the plan is a knee jerk reaction and would prove not only unworkable but actually counter-productive.

There is a large degree of support for the notion of holding parents responsible for the behaviour of their wayward children.

But opponents of the scheme believe penalising those who are already in difficult circumstances would only make matters worse.

It is also being noted that it is those ministers who would be most affected by the policy that are the most opposed to it.

However, for the time being at least, this plan has got the prime minister's personal seal of approval - it is certain to run for as long as he continues to push it.