The Association of British Drivers, which believes that speed limits should become advisory rather than compulsory and campaigns for the abolition of speed cameras, has used the No 10 website to secure more than 200,000 signatures.

The next most popular petition on the Downing Street site — petitions.pm.gov.uk — to repeal the Hunting Act 2004, has gained only 18,000 signatures The congestion charge petition was placed on the site by Peter Roberts, 46, who describes himself as an “ordinary motorist and account manager from Telford, Shropshire”.

The Times can reveal that Mr Roberts is a member of the association, which he joined two months before starting the petition. He also works in the car industry, supplying parts for Honda and Nissan.

An e-mail promoting the petition has been circulated widely by Mr Roberts and other members of the association. It contains several inaccuracies and paints an alarming picture of the impact of national road tolls on families.

It claims that the Government is planning to force drivers to spend up to £200 on a tracking device that will monitor all their movements, charge them £89 a month in road tolls and catch them every time that they exceed the speed limit.

It also claims that “all drivers will be paying far more than today”.

The Government is committed to holding congestion charging trials, probably in Birmingham or Manchester from 2010, but has made no decision on a national scheme, which it says is at least a decade away.

A study by the Department for Transport found that most drivers would pay less than they do now under a national system of road tolls. Ministers have said that other road taxes, such as vehicle excise duty or fuel duty, will be reduced if motorists are required to pay by the mile for road use.

The technology may also cost the motorist nothing because the DfT hopes to “piggyback” on technology being fitted to many modern cars, such as satellite navigation systems.

The Government has never suggested that the charging system would be used to monitor the speed of vehicles.

A DfT spokesman said: “This e-mail is misleading and factually incorrect. No decisions have been made on many of the things it claims are government policy.”