Around 2,500 post offices are to close under plans to put the network on a sustainable footing for the "email age", the Government confirmed today.

Trade and Industry Secretary Alistair Darling told MPs that the current size of the network could not be maintained after revealing that losses had grown to £4 million a week.

The Government also unveiled a £1.7 billion package, including an annual subsidy of £150 million, to prevent further closures and help the Royal Mail attract new business.

No details of where the cuts will fall were given on Thursday but consultations will now be held to identify branches which will close.

The National Pensioners Convention condemned the closures, pointing out that post offices offered a lifeline for millions of older people.

Vice president Dot Gibson said: "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 "very disappointing day" for communities across the country and said the Government should be doing more to help the Royal Mail win new business.

Mr Darling said the Government had strengthened protections for customers in rural and remote areas and widened the areas that will qualify for special protections for deprived urban communities following a public consultation since the closure announcement was made last year.