About 2,500 post offices - a fifth of those left in the UK - are to close by 2009, the government has confirmed.
Trade Secretary Alistair Darling, ahead of making a Commons statement on the closures, said the current loss-making network was "unsustainable".
He said 4 million fewer customers were using post offices every week than two years ago and it was losing £4m a week.
Opposition parties say further closures will devastate local communities, particularly in rural areas.
More than 4,000 post offices have shut in the past eight years.
The next round of closures "backed by £1.5bn investment from government" would contribute to a sustainable network, Mr Darling said. The network has been affected by the decision to pay pension and child benefit directly into bank accounts while TV licences, driving licences, passports and tax disks are now being supplied online and through other retailers.
Get the rest of the story here - http://news.bbc.co.uk/1/hi/uk_politics/6664109.stmhttp://news.bbc.co.uk/1/hi/uk_politics/6664109.stm