A petition signed by more than 10,000 people will be handed in at 10 Downing Street in a bid to save nine sub-post offices at risk of closure.

Lewes Liberal Democrat MP Norman Baker has been campaigning for post offices in his constituency to be kept open since Consignia announced it would be closing 3,000 nationwide.

Across Sussex, 80 urban post offices are at risk as Consignia battles to stem severe financial losses.

Mr Baker has identified nine post offices in Lewes, Seaford and Polegate which he has said are at risk of closure.

Consignia, however, has said no decisions have yet been taken on which post offices will close.

Mr Baker launched his petition in April this year and has since received a steady flow of signatures.

He said: "Local post offices are an essential part of the fabric of a community.

"They are particularly valued by elderly people, many of whom would be significantly inconvenienced if they had to make their way to a main post office in a town centre.

"A local post office also provides a friendly contact point which would be sadly missed were it to disappear.

"I am dismayed the ill-named Consignia is contemplating a raft of post office closures across my constituency and indeed across the country. This, of course, comes on top of plans to reduce the frequency of postal deliveries.

"I can assure my constituents I will be doing all I can to prevent the closure of any post offices within the Lewes area."

A spokeswoman for Consignia said: "We never want a post office branch to close. However, many urban post offices are struggling to survive.

"About 97 per cent of them are owned by the people who run them and as independent business people they have seen their incomes decline as fewer people use local shops.

"There are also too many post offices for the number of customers in many urban areas.

"In addition, from April 2003 the average post office stands to lose 41 per cent of its turnover when the Government stops paying benefits like pensions via post office benefit books."

She added that a public consultation process would begin at the end of November, with the first post offices closing in early 2003.

Mr Baker has said in Lewes post offices in Church Lane, Landport, Southover and St Annes may close.

In Seaford, he has claimed Alfriston Road, Chyngton Estate, Fairways Estate and Vale Road post offices could close and in Polegate Wannock post office was also at risk.

Sub-postmasters agreeing to close their branches are being offered up to 28 months remuneration as compensation.