The chief economist of the Institute of Directors has said the success of HS1 has falsely convinced the government to back a railway line linking London to the north.

James Sproule told a gathering of bosses at Hempstead House Hotel in Sittingbourne the positive impact of high-speed rail on towns such as Ashford and Gravesend is not an indicator government plans for HS2 will be a success.

He also said Kent was not under threat from the development of a northern powerhouse, which has become a focus of policy for the government.

“Part of the government’s plan has been to look at HS1 and how it has helped towns like Ashford, and hope the same impact will be received by HS2,” said Mr Sproule.

“There are several problems with HS2. There is no private sector money behind it, which means the numbers don’t add up.

“The country is still in a difficult financial situation and we only have the money for one big infrastructure project like this. Why is this one better than anything else?

“Why is it better than a new South East airport or national broadband or more tax cuts? I don’t know.”

He said IoD members wanted more spending on infrastructure and the extension of broadband.

“If there’s a single thing government can now do to help firms across the rural and urban community it would be to extend broadband,” he said.

“We need to communicate to compete and to deliver. In Kent a lot of people are working in smaller towns and like it because of the lifestyle – they are near friends and it is a nice place to raise their children. But they need to be able to communicate and connect themselves to their customers.”

He was dismissive when asked whether the northern powerhouse could threaten the South East.

He said: “I don’t see it happening. One of the really interesting things happening over the last 10 years is the cluster effect.

“You get areas of the world which are very effective. It’s a postive sprawl of area which attracts bright entrepreneurial intelligent people and gives a service for those people.

“They tend to become the postive areas of the world, and the South East is clearly a big part of that.”