It would cost at least £3 billion to move Medway’s gas terminal if plans for an international airport here went ahead.

That’s according to Rochester and Strood MP Mark Reckless, who has raised the figure with bosses at the plant.

He claims he was told it would cost a huge sum to move the National Grid’s £1bn gas import terminal on the Isle of Grain, pictured above, which is the largest in Britain.

Mr Reckless, left, was speaking after chiefs unveiled a new pipe to use waste heat from E.ON’s next-door power station at Grain LNG.

He said: “The National Grid was there and the manager of the LNG import terminal said it would cost at least £3 billion to move.

“He would like to know how Boris [Johnson] would pay for that, but we’ve had no answers.

“Then you would have to find another site for it that was suitable and which people didn’t object to.”

The Isle of Grain, the home of huge industry projects since the 1960s, is the target for a four-runway airport hub proposed by the architect Lord Foster (pictured below).

The government is examining the plan, which Medway’s political parties all oppose, as one of many to increase air capacity in the South East.

A final decision is only expected after the 2015 election.

National Grid refused to confirm the £3bn figure, saying it will give full evidence to the government.

A spokesman told the Messenger: “When the final airport plans are known, a full assessment of any impact on Grain LNG can be made.

“If a relocation of the importation terminal was required as part of this, a full assessment would need to be carried out to estimate the cost.”

The spokesman added: “National Grid will respond to the government’s call for evidence on the matter when it is published later this year, and we’ll do all we can to make sure the crucial role that our infrastructure plays in supplying Great Britain’s energy needs is taken into consideration.”