The Conservatives have set out plans to boost investment in Britain's motorway network.

Shadow transport secretary Tim Collins said that the government was falling behind its European counterparts when it comes to investing in the road network, with a potentially damaging impact on economic competitiveness.

The party aims to "close the gap" with the rest of Europe on the amount of high quality roads, trunk roads and motorways.

"We are the number two economy. We are the number two or three country in terms of population in Europe," Collins told BBC Radio 4's Today programme.

"But in terms of our motorway network we are about number 13."

Collins published research setting out a rebuttal of arguments that building extra capacity will increase the amount of traffic on the roads and create further gridlock.

He said the report "nails the assertion, often expressed, that building more roads simply creates more traffic".

Ministers have already announced some increases in road building in a bid to ease congestion at key blackspots, but the Conservatives said the government had not gone far enough.

"If you look actually at what the government has done they have simply restored a number of projects they axed in 1997 or 1998," Collins said.

"It still remains one of the smallest road building programmes in western Europe

"Even after it is completed, we still have many, many fewer miles of motorway than France, Germany or even smaller countries."

However, Collins said the extra investment would be phased in over several years.

He added that ministers should "recognise the government's principle asset is the £62 billion road network in this country".

"It has been significantly under-invested over many years. I would not pretend this just started in 1997," Collins said.

"We have a gap we have to close with the rest of Europe. If we don't, our business will face real competitive difficulties."