The government has rejected suggestions that MPs would be "skiving" off work, after they were granted two extra days away from Westminster in November.
Under an announcement by Commons leader Sir George Young last week, MPs will not sit on Wednesday 16 November and Thursday 17 November.
The change means they will be able to be away from Westminster from Tuesday evening until the following Monday morning.
The timetable was announced last week and Labour did not object. Bob Crow, the Rail, Maritime and Transport (RMT) union leader, told the Evening Standard on Monday that MPs had been "caught out on the skive".
But a Cabinet Office spokesman told the Huffington Post UK that the recess dates simply reflected a "restructuring" of the parliamentary calender designed to even out the time MPs spent in Westminster throughout the year.
"The House is sitting for more days in the first two years of this Parliament than in the first two years of the last Parliament," he said.
The spokesman claimed that under Labour Parliament sat for 133 days in the calendar year 2005 and 143 days in the calendar year 2006.
But he said under their timetable Parliament sat for 145 days in 2010 and is due to sit for 149 days in 2011.
"What it is the Leader's office is looking at is to structure the parliamentary year to ensure the House sits more evenly throughout the year rather than breaking up for a 82 day summer recess as it did under previous government."
But a spokesman for the Public and Commercial Services Union that represents civil servants said sending MPs away from the Commons would makes it easier for the government to push through its austerity measures.
"The basic point is that the government forcing through cuts at breakneck speed, and MPs need all the time possible in the House to hold the government to account," he said.
This year MPs have also been called back to Westminster during recesses to debate the riots that hit English cities over the summer, phone hacking and the military operations in Libya.
MPs will be asked to approve the recess dates in a vote this evening.