Britain's youngest MP Jo Swinson called in at Wootton's sub-post office, near Abingdon, and pledged her support for a "vital community life-line" for villagers.

Miss Swinson, 26, is the MP for East Dunbartonshire and Liberal Democrat Shadow Secretary of State for Scotland.

Before meeting Lib Dem students at Oxford University and addressing the Oxford Women in Politics group, she visited Sandleigh post office and shop in Wootton.

Ms Swinson said: "This is a vital part of the community. It is a life-line for many people, particularly the elderly.

"Many small post offices throughout the country are under threat of closure. Although Wootton's post office is thriving, it could be in danger as the Government reduces many of the services post offices provide.

"By axing key services such as the Post Office Card Accounts (Poca) the Government is sounding the death knell for thousands of local post offices.

"Of course post offices have to look at new services to increase revenue streams, but the big worry is that more and more services are being stripped away and that is going to make it more difficult for small places to survive."

Wootton post office collected more than 500 signatures on a petition calling on the Government not to withdraw the Poca that allows pensioners to withdraw their pensions. The idea is that, from 2010, pensions will be paid into bank accounts.

Postmistress at Wootton for the last 18 years, Margarita Morgan, said: "This post office is not under threat of closure but it may be if the Government continues to take away services such as television licenses, car tax and pensions.

"It's all very well switching pensions to bank accounts, but not every pensioner has a bank account. They like to have the money separate from other expenditure so they know what they're dealing with week to week."

Mrs Morgan said she received a Government subsidy towards running the business and that was vital because it was a shop that did not sell food. She said: "We would not be able to carry on without a subsidy because the usual bills have to be paid, staff, rent and fuel. This shop is essential to Wootton. If we closed, people would have to travel into Abingdon and then they would shop there and not use other village shops."

Customer Phillipa Henry said: "I don't know where we would be without the post office. It is such a friendly place. I used to get my Disability Living Allowance from there and TV licence but I can't do that now. Services are being eroded, forcing people to travel to Abingdon."