A mature oak has probably become the most expensive tree in Britain after a deep-rooted legal battle means its must be preserved at a cost of more than £50,000.

The tree's owner wanted it felled as it was causing subsidence to his semi-detached home in Great Dunmow in Essex.

The decision was supported by the property owner's insurers Axa, which said the alternative of expensive underpinning could eventually cost £50,000.

The oak however appeared to be protected by a preservation order and could not be cut down.

The home owner appealed to the district planning inspector for him to drop the tree preservation order, but was turned down.

Undeterred, the house owner launched a legal battle against the environment secretary, John Prescott, to have the earlier decision overturned.

This time the home owner claimed the TPO had been improperly served by his local authority, Uttlesford District Council.

He said the council had failed to correctly issue a Certificate under Article 5 of the Town & Country Planning Act, stating why the tree should be saved.

The case may have again ended in defeat for the owner but Axa claims the case has established important principles over the status of TPOs. Roy Blakeman, technical claims manager at Axa, said the latest decision was flawed: “Had common sense prevailed the cost of putting the subsidence right would have been reduced to a few thousand pounds, compared to £50,000 for extensive underpinning.”

Uttlesford council declined to comment as the case may be appealed.