According to published reports, the government has been trying hard to avoid a repeat of protests that practically shut down the country in September and has promised to get tough if fuel supplies are threatened by the demonstrators.
Police leaflets were handed out to protestors this week that said: "Any driver that cannot maintain normal road speed will be safely removed. Failure to comply will make drivers liable to prosecution."
Truckers, farmers and other groups have been demanding big cuts in fuel taxes, and seem committed to the convoy that spreads from Newcastle in Northern England to London.
People's Fuel Lobby chairman David Handley said he and his colleagues, who want the tax cuts by Nov. 13, had a democratic right to protest. "Is this is a democratic country or is this now turning into a police state?" he asked.
London police have set up an exclusion zone around their city to prevent the convoy from entering the city center. According to published reports, the motorcade of trucks will be stopped when it reached the M25 motorway circling the capital.
About 50 vehicles are taking part in the 280-mile journey, far fewer than predicted by organizers.
A police spokeswoman said the exclusion order affected goods vehicles which were not on bona fide business. The ban was legal under the provisions of the Metropolitan Police Act of 1939, which gave protection to parliament, when it was in session, from disruptive demonstrations, reports said.
The stakes are high for both Prime Minister Tony Blair and the protesters, according to news reports. The September protests dealt a sharp blow to the popularity of the ruling Labor Party, which fell behind the Conservatives in opinion polls for the first time since the 1997 general election.