Hundreds of trucks will converge on Cardiff tomorrow in protest against soaring fuel prices - even though all the other protests across the UK have been postponed.

Andrew Spence, a senior spokesperson for the Fuel Lobby, said it was "too late in the day to postpone it", but demonstrations across the country on Wednesday would not now go ahead.

He said: "With Gordon Brown's remarks yesterday, we feel it is a positive sign in the right direction. We are being sensitive at the moment, especially when the government is making positive dialogue, so we are prepared to give Mr Brown the benefit of the doubt and see what his proposals are.

"We are planning to hold a number of meetings with Government officials in the coming weeks to argue our case.

"The Government is not wanting to seek protests and we are not wanting to carry out protests."

But he warned: "This is only a postponement and if we do not get the continuation of positive dialogue, there will be no more warnings given."

David Handley, chairman of Farmers for Action, said: "We met last night following Gordon Brown's announcement that he is reconsidering increasing duty in September and also the fact that with the move from Opec yesterday we certainly will not be taking further action for the next two to three weeks.

"Gordon Brown has clearly indicated he is going to look and go back and reinvestigate the increase. We feel we should give him two to three weeks - you can still protest in September."

Mr Brown said last night: "Rather than opportunistic, short-term, day-to-day reactions to fast-changing events - which do nothing for stability - I will review progress in August."

A South Wales Police spokesman said about 300 trucks were set to attend the demonstration tomorrow.

The majority are expected to be travelling from the Cross Hands area of West Wales along the M4 motorway towards Cardiff, he said.

The spokesman said they will meet protesters from other areas near the Cardiff West services at lunchtime, before making their way into the city centre.

David Davies, a Conservative Member of the Welsh Assembly, said he would be addressing tomorrow's rally in Cardiff.

Mr Davies, who holds a class one HGV licence and worked as a driver in the family haulage business prior to being elected, said the protesters were "proud hard-working people".

He said: "The Government have got to realise that if they continue to take £4 out of every five spent on fuel then the haulage industry in this country is going to grind to a halt.

"The people taking part in the rally tomorrow are not trouble makers, they are proud hard working people, yet they are being driven out of existence by the scandalously high taxes levied on fuel to pay for this governments spending spree."

Mr Davies, who represents Monmouth in the Assembly, said he was proud to be taking part in the protest.

"I hope the Government will now wake up and start to realise how angry people are getting," he added.