The threatened closure of four post offices in Sutton may not only spell the demise of a traditional focal point for the local community, but also damage the environment.

Environmentalists fear the closure of branches in Carshalton and Sutton will mark an increase in short car journeys, as customers are forced to travel further to use alternative services.

Statistics from the Department for Transport show foot journeys are already falling an estimated 15 per cent and bike journeys down by 14 per cent.

Now campaigners fear the trend for people to pop in their cars will only increase as they will have further to go to find a branch.

Carshalton and Wallington MP Tom Brake said the situation contradicted the Government's drive to cut carbon dioxide emissions, and questioned the Secretary of State for Transport, Ruth Kelly MP, on the rationale.

"How much further does she expect the number of such trips to fall as a result of the programme of 2,500 post office closures?" he asked.

"Has she been able to assess how many extra short car journeys will need to be made as a result of that closure programme?"

In reply, Ms Kelly said the key was to encourage local leadership to think about how people get around, and noted how in Sutton sustainable travel initiative are already seeing the dramatic effect that residents can have by cycling and walking.

"Mr Brake is absolutely right to say that where the critical local infrastructure, the post office, the school, the local shops, is located matters enormously," Ms Kelly said.

"That is why it is important for us to work with the Department for Communities and Local Government to look at the planning system, to ensure that people can get about easily on foot or by bike."

Mr Brake added: "It is clear that even the Secretary of State is having to acknowledge that, as well as making the lives of many senior citizens and people with mobility problems very difficult, post office closures will damage Government attempts to tempt people out of their cars."