The government is to sell off its 40% stake in the Eurostar rail service to help fund a range of major infrastructure projects aimed at boosting the economy.

The money raised will contribute to about £375bn of investment in energy, transport, communications, and water projects up to 2020.

The sell-off of Eurostar stake could potentially raise hundreds of millions of pounds.

The company, which is majority-owned by the French state rail firm, SNCF, more than doubled profits to £52m last year.

The high-speed service connects Kent and London with Paris and Brussels, via international stations at Ashford and Ebbsfleet.

The Chief Secretary to the Treasury, Danny Alexander, said: “Underground, overground, onshore, offshore, wired or wireless, tarmac or train track. You name it, we’re building it right now.

"This is great news for the people of the UK.”

In a BBC interview, he said:"The most important thing we've done as a government is create an environment in which people want to come in and invest in British infrastructure."

But he admitted that the UK had "underinvested...over several decades".

Included in the new National Infrastructure Plan (NIP) being announced today are a further £50m for a redevelopment of the railway station at Gatwick Airport.

Last month, Eurostar posted a rise in revenues and passenger numbers compared with last summer.