Business leaders have joined opposition to plans for a £30 billion high speed railway as Ministers come under increasing pressure to think again.

The Federation of Small Businesses called for the cash to be invested in improving Britain’s road network instead.

And leading local employer Chris Kelly, chairman of West Bromwich-based Keltruck Ltd, said many employers would prefer to see investment in the road network – which is used to transport the overwhelming majority of freight.

Up to 60 campaigning groups have been formed along the proposed route, but the backing of senior figures in the business community will provide a major boost to opponents of the Government’s plan for a new high speed rail line between Birmingham and London.

Matthew Jaffa, deputy head of policy at the Federation of Small Businesses, made it clear that not all employers are convinced, as he spoke to the Transport Select Committee in the House of Commons this week.

He was giving evidence to the committee as it holds an inquiry into the economic benefits of transport, which will have a strong focus on high speed rail.

Mr Jaffa said the Federation of Small Businesses had surveyed its members but “not one of our members said high speed rail was a critical concern to them”.

Improving the road network was more important to small businesses, he said – but money was being poured into rail instead.

‘‘Before a sign-off for high speed rail is undertaken, we need to be certain that the need for that outweighs the need for investment in the road network.”

Mr Jaffa pointed out that road users contributed £45 billion a year to the Treasury, but only £9 billion actually went back to the road network.

Giving evidence to the same inquiry, Matthew Farrow, head of infrastructure and planning for the CBI, said businesses in his organisation wanted high speed rail to go ahead because the West Coast Main Line was close to running out of capacity.

But the planned London to Birmingham service must not be allowed to prevent other schemes getting funding, he said.

“It is important if High Speed Two goes forward that it doesn’t suck up the transport budget.”

Mr Kelly, who is also deputy chairman of the Midlands Industrial Council, a group of senior business leaders which has made donations to the Conservative Party, said: “They are talking about spending countless billions of pounds on a rail link when our roads are in absolutely dire straits.”

He said millions had already been spent upgrading the West Coast Main Line even though Government figures show 87 per cent of domestic freight, excluding coal and petrol, is transported by road.

Mr Kelly said: “Law firms where people travel to meetings in London may be excited about high speed rail but businesses which actually move goods have different priorities.”

The high speed service is likely to include a spur which would be built through a business park owned by another senior West Midlands business figure, Robert Edmiston, at Coleshill – the head office of his business International Motors Limited.

Mr Edmiston, soon to be known as Lord Edmiston after he was awarded a peerage, said he was “not yet convinced” of the case for high speed rail but would not “blackmail” the Government.

Meanwhile, Conservative MPs in constituencies that may be affected by new rail lines are coming under increasing pressure.

Conservative whip Michael Fabricant (Con Lichfield) said he was still considering the case for high speed rail, after the cabinet of his local council, Staffordshire County Council, opposed the scheme.

He said: “I remain to be convinced that there is an economic case for HS2. But I have an open mind on this.

‘‘In the meantime, I must ensure that any proposed route that goes through my constituency minimises any effect on my constituents.

‘‘Therefore the route that HS2 might take is critical.”

He is one of a number of senior Conservatives to express concern. Cheryl Gillan, the Welsh Secretary and MP for Chesham and Amersham, one of the areas that would be worst-affected by the line, and David Lidington, the Foreign Office Minister and MP for Aylesbury, have both said they will vote against it.

And Jeremy Wright, MP for Kenilworth and Southam in Warwickshire, said he would quit as a Government whip if the role prevented him speaking out against the proposals, although he did not believe that would happen.