The government's decision to close at least 2,500 post offices by 2009, has been condemned for dealing a "devastating blow" to the lives of millions of pensioners.

The government's decision to close at least 2,500 post offices by 2009, has been condemned for dealing a "devastating blow" to the lives of millions of pensioners.

Trade and Industry Secretary Alistair Darling will tell MPs later that proposals outlined last year to reduce the size of the network to about 12,000 will go ahead.

He said four 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 closures - a fifth of those left in the UK - "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.

The National Pensioners Convention condemned the closure decision.

Vice President Dot Gibson said: "For millions of older people living in both urban and rural areas the post office provided a lifeline not only to services but also to community life and information.

"The Government claims the network is unsustainable but at least £260 million has been lost because ministers decided, against the wishes of many older people, to pay pensions directly into bank accounts.'

The group said many pensioners will now have to rely on other people to take them to a post office, which was a "disgrace'.

Susan Kramer, trade and industry spokeswoman for the Liberal Democrats, said the Government was sounding "the death knell' for many communities".

The Conservatives said it was a was a "very disappointing day' for many local communities across the country and said the Government should be doing more to help the Royal Mail win new business.