That is the pledge made by Shadow Transport Secretary Chris Grayling following the Government's failure to honour its own action promise to the UK haulage industry.

After Labour ministers dumped plans to introduce a system of 'lorry road user charging' - designed to close the yawning gap between fuel and road tax levies applying on the Continent and in the UK - Mr Grayling told the haulage industry: "The next Conservative government will find a way to level the playing field."

He declared: "We can't guarantee to remove all the competitive disadvantages you face. Some, like pay rates, are beyond our control. But we need to find a way of ensuring that all heavy goods vehicles using Britain's roads make a comparable contribution for doing so, and of ensuring that the rules on drivers' hours and vehicle roadworthiness are properly enforced."

In a speech to the Transport Association, Mr Grayling signalled that the reactivation of a lorry road user charging system was a strong possibility, under the next Conservative administration.

He said: "I know the concept has been discredited by the broken promises of the current Government, but that doesn't mean it is necessarily the wrong option. It has already happened in Germany, where all trucks now pay to drive on Germany's major roads. The system is not perfect, but it does appear to work."

Mr Grayling added: "It has ensured that overseas hauliers using German roads pay towards their costs. And it has had the benefit of dramatically improving the environmental quality of the trucks operating in Germany, by incentivising Euro 4 and 5 vehicles, and discouraging older, less environmentally friendly vehicles."

Revealing that Shadow Roads Minister Owen Paterson is currently examining the various possible options, including a scheme to levy an embarkation fee on all lorries entering the UK at the ports, with revenues used to reduce duty levels on domestic vehicles, Mr Grayling said a discussion paper would be published next year.