TONY BLAIR yesterday appeared to rule out reversing the latest fuel tax increase despite fears that rising oil prices could spark new mass protests.

The Prime Minister's official spokesman insisted the premier would not intervene to halt price rises at the pumps.

Instead, Britain would join other countries urging the Organisation of Petroleum Exporting Countries (Opec) to increase production to fend off fresh increases in the price of crude.

Opec meets in Beirut tomorrow with the latest terrorist outrage in Saudi Arabia - which left 22 dead, including British oil executive Michael Hamilton - sparking fears of further price rises.

But Petrol Retailers Association director Roy Holloway warned increases had been inevitable even before the hostage-taking in Saudi.

A signal by the Chancellor of the Exchequer that he would be prepared to change his mind about the planned 2p rise on fuel duty this September could be enough to ward off any petrol price protests, he said.

The price of crude in New York was back above the $41 a barrel mark last night, rising by 4.1 per cent in electronic trading. In the UK, the cost of crude increased by 4.9 per cent.

Mr Blair's official spokes-man said: ''The Prime Minister does not determine the price of petrol.

''It's not for the Prime Minister to indulge in TV reality shows and judge the price of the oil market.

''It's for the Prime Minister to work with his colleagues, and, as we will be doing at the Opec meeting on Thursday, make representations to Opec and others."

But Mr Holloway said: ''Unless the Government reverses its tax position, there is no way of halting the rise in fuel prices this year.

"Fuel protestors would be much less likely to take action if the Chancellor was to reconsider his September 1 fuel duty rise.''

His comments came as a survey showed drivers would back fresh demonstrations against price increase.

As many as 70 per cent of motorists would support fuel blockades, according to research for the motor insurance company Churchill.