Gas and fuel plants in south Essex could be protected by military police because of terror fears.

The Home Office is considering bringing in Ministry of Defence police to guard industrial plants such as Coryton, in Thurrock, and possibly the Calor Gas site, in Canvey, against the threat of terrorism.

Calor plans to expand its current terminal in Thames Road and store 108,000 tons of liquefied natural gas - 5 per cent of the country's gas needs.

Although its planning application was turned down by Castle Point Council, it is thought it will appeal against the decision.

Fears that terrorist group al-Queda is showing an interest in some gas and oil plants have been raised following national media stories claiming to have seen intelligence reports.

Staff at the Home Office confirmed they were looking at manning oil and gas terminals.

A spokesperson said: "We cannot comment on individual installations.

"The Ministry of Defence police would be part of a package of protective security measures we are deploying.

"We are at a severe risk of terrorism."

Andrew Ford, corporate affairs manager for Calor Gas, said the company had not yet been involved in any discussions with the Government.

He said: "We haven't had any contact with the Home Office as yet and it would depend on how they defined what installations they would protect.

"It is fairly early days yet."

George Whatley, chairman of protest group People Against Methane, who are fighting Calor's plans, said his fear was the extent of the damage that could be caused by any terrorist action.

He said: "These are soft targets, but if they are hit it would cripple the country.

"If the site on Canvey is supposed to have 5 per cent of the country's gas supplies, it would not only be that percentage that would be crippled, but it would be the domino effect that would be the real problem.

"Within seven miles you have got another site at the Isle of Grain, in Kent, and oil installations down the river."