An excavation will begin to dig up a Spitfire from the field where it has lain for 75 years since it crashed during the Second World War.

Archaeologists hope to recover surviving parts of the plane from the Cambridgeshire peat before the agricultural landscape is restored to wetlands as part of a major conservation project.

After the excavation, which begins today, the land, owned by the Wildlife Trust for Bedfordshire, Cambridgeshire and Northamptonshire, will continue to be turned into natural habitat to link up remaining fragments of fenland and create a 14 square mile Great Fen landscape.

Pilot officer Harold Edwin Penketh was just 20 when he died in the crash near Holme Lode Farm, Holme, on November 22, 1940, on a training flight, after what was thought to be a failure of the oxygen system or a physical failure of the plane.

The pilot's body was recovered from the crash and taken for burial in his home town of Brighton, but the remains of the plane, which had plummeted vertically into the ground at high speed, were left to vanish into the peat.

Standing in the field, which has been converted from arable to grassland as part of the transformation to natural habitat, before the dig it would be impossible to know that the remains of a Mark 1 Spitfire lies underneath.

But geophysical surveying by Cranfield University appears to have pinpointed exactly where the wreckage is and this week a team of archaeologists and volunteers hope to extract parts of the plane including the Merlin engine and its guns.

The team will include people from the Defence Archaeology Group which oversees Operation Nightingale, a scheme using archaeology to help the recovery of injured veterans and service personnel.

Oxford Archaeology East senior project manager Stephen Macaulay, who is overseeing the dig, said it was unusual for archaeologists to excavate where they knew the names of people involved in the event, in this case ''somebody who lost their life, a young man learning to fly, defending his country''.

Digging in the peat would be challenging as it could be very waterlogged, but those conditions are likely to have preserved the plane better, he said.

''It's really exciting, it's a real challenge. I've done all sorts of archaeology across the world, but to be able to say we've dug up a Spitfire, that's up alongside anything I've done.''

The Great Fen Project's Kate Carver said now was the ''window of opportunity to get the Spitfire out'' as the site was slowly being transformed from grassland into fen bog to create to create habitats for wildlife such as birds of prey, cranes and dragonflies as well as green space for people.

''We're raising the water tables over the whole site over the next five years, so it's going to get progressively wetter.

''If we don't do it now, it's not going to happen. It's also the 75th anniversary of the Battle of Britain so it all came together.''

The excavation will be a celebration of Pilot Officer Penketh's life, as well as commemorating his death, she said.

''When so many young men died in the war, unrecognised and unknown, it's a really nice opportunity to give him some recognition.''

After the dig, the hole will be filled in, artefacts removed and cleaned with plans to eventually put them on display, and the process to restore the wild fenland will continue.

''Within a couple of months you won't know anything has happened there,'' Ms Carver said, although there are plans to put a memorial to Pilot Officer Penketh on the bridge leading to the site.