A protester who caused city centre chaos after camping in a tree for almost two weeks will not face criminal charges.

Police this week dropped the case against homeless Gabriel Chamberlain, 34, who spent 12 days in a Bonn Square tree house in January.

He was protesting against Oxford City Council's redevelopment of the square, which involved cutting down trees.

At one stage police set up a ring of steel around the treehouse threatening anyone who entered the square with arrest for trespass.

The operation, which cost the council £12,000, was last night criticised as a waste of taxpayers' money.

Police have declined to reveal how much the protest cost despite a Freedom of Information request by the Oxford Mail.

Chief Insp Jack Malhi said police did not have enough witness statements to charge Mr Chamberlain following his arrest for aggravated trespass.

He also believed a court case would be a waste of public funds.

Mr Chamberlain's mother Josephine Knight-Jacobs said: "It was absolutely ridiculous to put all those police and council resources into it, not to mention how much money they spent. It was a waste of police and taxpayers' money.

"It was a waste of time arresting Gabriel in the first place. The council and police should have just left the square alone. It's dreadful what's going on."

Last night Gabriel said: "I'm just sick and tired of the whole thing. I hope they will just leave me alone."

The homeless eco-protester began his tree-top protest hours before Oxford City Council planned to chop down the 100-year-old trees as part of the £1.5m redevelopment.

As temperatures plunged below freezing, passers-by gathered around his tree-top vigil and 3,000 people signed a petition backing his protest.

At one stage police and council security staff closed the square, installed spotlights on the treehouse and even arrested, then released, a man for giving Mr Chamberlain some water.

After 12 days the council secured a possession order.

Police then arrested Mr Chamberlain on suspicion of aggravated trespass when he climbed down.

Chief Insp Jack Malhi said the decision not to press charges was common sense, and police had experienced difficulties collecting enough witness statements.

He said: "The idea was to achieve a peaceful resolution and allow the council to continue work.

"The protest caused a lot of inconvenience and is not a good thing to do, but each case is decided on its own merits.

"We have not prosecuted this time, but that does not mean we would not if someone does it again.

"In this particular case it would have been a waste of money to take this man to court.

"The best we could have got was a fine and we would have probably been chasing the money for a long time.

"We achieved a peaceful resolution and the arrest was the most appropriate tactic."