The spectre of national road pricing is one step closer after the newly-appointed secretary of state for transport Paul Clark refused to rule out that a series of trials about to get underway was not the precursor to a nationwide system of pay-per-mile road pricing.

The trials begin in the New Year and will involve real-world tracking that could eventually lead to ‘spy-in-the-sky road pricing’.

However Minister Clark said there is a long way to go before any conclusions can be drawn and the trials are aimed at “giving local authorities the tools they need” to introduce local road pricing.

The government has been inconsistent in its message to businesses about its plans for a national road pricing scheme as a way of addressing congestion and transport pollution.

The minister agreed that doing nothing is not an option.

“Congestion is bad for business,” he said, pointing out that 90% of goods are still transported on the roads.

“Businesses rely on good road access – even an increase of just one or two per cent in the number of miles travelled will lead to gridlock – if left unchecked congestion will cost £22 billion by 2022.”

However, he was evasive about whether the results of local road charging in Manchester – the future of which will be decided on in a postal ballot on December 11 - and another road charging scheme planned for Cambridge, as well as trials of road pricing technology funded by the Department for Transport could all eventually be used for a national road pricing scheme.

Mr Clark did give assurances to delegates at a Transport Times road pricing conference that a national road pricing scheme was not planned in the short to medium-term.

Solutions already being introduced nationally include hard-shoulder running and active traffic management schemes on motorways.

But even here, businesses should expect single lane tolls, which will be introduced after legislation is passed allowing such charges.

Opposition transport spokesmen were quick to criticise the new minister, with shadow transport spokesman, Stephen Hammond, reiterating that the Conservatives would not introduce a national scheme.

“We are against any form of national road pricing,” he said.

The Liberal Democrat transport spokesman, Norman Baker said his party, while in favour of a national scheme, would ensure it was revenue neutral by reducing fuel duty, introducing a charge for lorries and abolishing VED.

“Road pricing works,” he said. “But it should not be a financial penalty on motorists.”