Pressure was mounting on Chancellor Alistair Darling last night over proposals to axe post offices in his constituency.

The Herald revealed yesterday that there could be as many as 39 post offices in Edinburgh, Lothians and the Borders hit by the plans which are due to be confirmed next week. Four of the 13 earmarked for closure in Edinburgh are in Mr Darling's South West constituency.

The Chancellor was described as the architect of the closures after he announced the plans to cut 2500 post offices across the UK last year.

Opposition politicians said the backlash could be enough to cost him seat.

The Scottish Tories said they were already planning to target his constituency. The party said last night that the post office closure programme would work against him at constituency level. He has also had a troubled time in the Chancellor's job, with the Northern Rock crisis and the loss of 25 million people's personal details from the department he heads.

He is also holding the purse strings during the credit crunch, a difficult period for the Treasury.

A spokesman for the Scottish Tories said: "Our polling has shown that there are a clutch of seats within our grasp and that includes Alistair Darling's. People will wonder ... if Mr Darling has any desire to save his seat."

Shirley-Anne Somerville, SNP Lothians MSP, said that "it looks like the chickens are finally coming home to roost for Chancellor Darling with four post offices earmarked for closure in his own backyard". She added: "The Labour Party has run down the network for years and now the Post Office has been given a fixed number to close in the city, no matter how viable the branches may be."

Mike Pringle, LibDem MSP for Edinburgh, said: "Is Mr Darling going to campaign against the closures in his own constituency? It will be an interesting scenario."

Mr Darling said Post Offices were losing money. He added that he would discuss the plans with his constituents and postmasters involved.

The four earmarked for closure in his constituency are Gorgie, Longstone, Shandon and Calder Crossway.

The wider plans which include running part-time Post Offices from any available outlet - possibly including an equestrian centre in East Lothian - were broadly criticised.

One group supporting older people said the move to consult to close or downgrade 258 of the 1638 Post Offices in Scotland would affect the most vulnerable.

A spokesman for Age Concern Scotland said: "The majority of older people in Scotland consider their post office to be a lifeline, with many relying on the Post Office as a one-stop shop to access cash and benefits, pay bills, get advice and information, and socialise.

"Further cuts in the network without effective alternate services, now or in the future, would risk leaving many vulnerable older people socially isolated and struggling to access essential services."

Anne Moffat, Labour MP for East Lothian where there could be seven closures, was said to have endured a barrage of criticism from nearly 100 residents at a public meeting over the closures.

Derek Brownlee, Tory MSP for South of Scotland, said that "the government seems hell-bent on closing as many post offices as possible".

"I am sure there will be wide concern at any proposals to downgrade services."

The consultation over closures lasts six weeks.