Boris Johnston fended off difficult questions about train station zoning on a walk about in Surbiton as he drummed up support in his bid for re-election.

The London Mayor was responding to claims he had broken a promise to help move Kingston and Surbiton stations from zone 5 to zone 6, placing the blame on Lib Dem MP Edward Davey and train operators.

He backed the campaign before his election in 2008, even saying he would stump up the cash, but emphasised he has no powers to push South West Trains to make the move.

He said: "It is up to Edward Davey to make this happen.

"The reality is this is a decision for the train companies to agree to and that is why the government should be sitting on this.

"I do not know why he has not sorted this out. He is, after all, a government minster now.

"The way forward is to give me more power over the underground networks and that way we would get a solution."

A spokeswoman on behalf of Edward Davey said the Energy Secretary was meeting with relevant minsters and still pushing for the re-zoning.

She said: "This is till Edward’s aim. He is pushing on this, meeting minsters and work to make it happen.

"The idea that Boris could blame Edward is totally ludicrous."

On Monday's walkabout, down St Mark’s Hill, through Surbiton station and then off down Victoria Road, Boris promised better police presences in the borough and talked about his bike scheme coming to Kingston.

He had spent the earlier part of the day talking to shop keepers and residents in Chessington.