Ministers have delayed a decision on a new toll motorway linking Birmingham and Manchester after revealing "no consensus" exists on the proposals.

They have ordered a new inquiry to determine the costs and benefits of building a new motorway instead of widening the existing M6.

Proposals for an M6 Expressway, providing a tolled two-lane expressway in both directions, were unveiled last July.

Existing plans to widen the motorway by one lane in each direction, first announced in 2002, were put on hold while the Government launched a consultation on the scheme.

Approximately 9,500 responses were received by October last year, but last night Transport Minister Stephen Ladyman asked the Highways Agency, the Government body responsible for Britain's road network, to carry out a new feasibility study.

Business leaders insist the region urgently needs more road capacity.

But Howard Marshall, of the West Midlands CBI, said: "The technical aspects are crucial and I would welcome the study if it is going to look at those, and how the different options can add value to the West Midlands' economy."

Dr Ladyman said: " Providing additional capacity to the M6 between Birmingham and

Manchester, whether in the form of widening the existing motorway to a tolled Expressway, will require a huge investment.

"It is vital that we examine the options carefully and choose the right way to provide the capacity needed."

He added: "While it is clear that there is no consensus in favour of the Expressway proposition, the option is no more than an outline at this stage.

"More evidence on the widening and Expressway propositions is needed before a decision on a preferred option can be taken. I have therefore asked the Highways Agency to carry out detailed development work on the Expressway and a feasibility study to compare the impacts of the costs and benefits of the Expressway against those of widening."

Whichever option is chosen, the road would be open for traffic by 2016, he said.

The 50-mile M6 Expressway would run parallel to the M6 from junction 11A, near Cannock in Staffordshire, to junction 19, near Knutsford in Cheshire.

It would be only the second pay-as-you-go road, following the opening in December 2003 of the 27-mile M6 Toll.

If it goes ahead, the scheme would replace plans to widen the junctions 11 to 19 stretch of the M6 from three lanes to four.

Stafford MP David Kidney (Lab) welcomed the new study. He said: "It makes sense to appraise both schemes side by side. Plans will be developed for both options and this will allow the public to weigh the advantages and disadvantages for each scheme."

He added: "I remember how many people complained that the consultation over the proposed Expressway was difficult to judge because there was so little detail provided."

Birmingham City Council leader Mike Whitby stressed the importance of improving the city's transport links yesterday.

He said: "It is essential for Birmingham and the city region, but also essential for the nation as a whole and economic growth across the country."