A group of travellers descended on Westcroft Leisure Centre last night with "operational precision".

Around 30 vehicles arrived at the car park of the centre, which is due to close on friday for a multi-million pound refurbishment.

A witness, who was working out at the gym said the travellers "swooped" on the car park like it was "operationally planned".

John Lynch, 61, said: "There were cars driving in with caravans in their droves, then the cars would spin round and come back with more caravans. It was a slick operation and it appeared to be very well planned."

Mr Lynch said the group were "driving incredibly recklessly".

At one point, Mr Lynch said youngsters from the group were throwing objects at the gym, but the older members of the group were quite polite.

Mr Abbott said: "Some of the older members of the group offered to pay to use the showers."

A spokesman for Sutton Council said officers were working with the police to tackle the situation.

He said: "The car park is there to make it easier for residents to access the sports facilities – it isn't a suitable location for temporary housing. We are asking the travellers to move on to a more appropriate area and will start legal proceedings if necessary.

"Measures are also being taken to stop travellers setting up camp there during the closure period."