Prominent Cabinet members have been accused of "rank hypocrisy" after apparently campaigning against government policy to shore up support in their own constituencies.
Seven members of Gordon Brown's government have campaigned against local Post Office closures, despite the government ordering 2,500 branches to close by the end of the year.
They include justice secretary Jack Straw, home secretary Jacqui Smith and Olympics minister Tessa Jowell, all of whom were in the Cabinet when the closures were approved.
Culture secretary Andy Burnham, skills secretary John Denham, Welsh secretary Paul Murphy and chief whip Geoff Hoon have also campaigned against closures in their own constituencies.
Charles Hendry, shadow post office minister, said the Cabinet members' stance was "nimbyism and rank hypocrisy of the worst kind".
He said: "It is unbelievable that some of the Cabinet ministers who decided that 2,500 post offices must close are campaigning to save the ones in their own constituencies."
However, post office minister Pat McFadden said it was possible for MPs to have concerns with local closures while still accepting the government policy.
Jack Straw, for example, had argued the case for nationwide closures to his constituents but was campaigning against specific closures, Mr McFadden explained.
Ministers argue the 2,500 closures are necessary to stem the Post Office's losses, estimated at £4 million a week.
Mr McFadden said that amid such multi-million losses it was government policy to reduce the network's size but specific closures would be based on local consultations.
Speaking to the Today programme he said it was right MPs take part at this local level, with closures determined by specific factors including public transport, deprivation and planned building works.
It is "right that MPs of either party represent their constituents views on this," he said, insisting it would be "odd" if Cabinet members did not voice their constituents' views.