The BBC's Karen Ainley: "The chance of anyone surviving is remote"

A massive search on Christmas Eve after the plane crashed at about 1400 GMT failed to find the pilot .

A helicopter equipped with thermal imaging equipment was being used to scour the area, coastguards said.

Earlier a police helicopter found a seat and a flying helmet floating among the debris from the plane.

The emergency services warned that anyone in the sea would only have had hours to live because of the low temperature of the water and the unnamed man, who is believed to be in his 30s, was now unlikely to be found alive.

An eyewitness who raised the alarm reported a parachute leaving the twin-seater plane as it hit the water.

Coastguards located a wreck, stuck in the Bradwell-on-Sea mud flats about a mile out to sea. There was no sign of the pilot.

Resuers were hoping the retreating tide would uncover any wreckage on the mud flats and allow them to check that the pilot had managed to escape from the ex-RAF trainer plane which was fitted with ejector seats.