The Government has played down reports that motorists using stretches of the M20 and M25 could eventually pay to use new toll lanes.

But other proposals to allow motorists to use the hard shoulder of both motorways at busy times remain on the agenda, as does the prospect of a system already in use on the M25 to manage motorists’ speeds through variable speed limits.

There has been renewed speculation that if the use of the hard shoulder is allowed along some parts of the motorway network, then drivers could be asked to pay a toll to use a fast outside lane.

It follows reports that new transport minister Lord Adonis is interested in the idea of toll lanes.

The possible use of the hard shoulder along 500 miles of motorway was announced by former transport minister Ruth Kelly earlier this year.

However, the Department for Transport inisted any plans for motorists to use the hard shoulder were separate from its examination of whether tolls could be introduced.

In a statement, the DfT said that while various options were being considered, no specific proposals had yet been put forward.

"We have made it clear that we are at a very early stage of looking at a range of options for managing demand on new motorway capacity, including tolled lanes and car sharing lanes. We would need new primary legislation before any tolled lanes could be introduced – even on a trial basis," a spokesman said.