A government minister has declined to confirm whether the next general election will be fought on new parliamentary constituency boundaries.
Constitutional Reform Minister Chloe Smith said it would depend on the outcome of a vote on the proposals.
Ms Smith was responding to veteran Conservative MP Christopher Chope who asked whether she could "guarantee" that the new boundaries would be implemented in time for the election, due in 2015.
The exchanges came during Deputy PM Nick Clegg's monthly question session with MPs on 8 January 2013.
The Liberal Democrats want to postpone plans to cut the number of MPs from 650 to 600 - a flagship Conservative policy - until after the 2015 election, after failing to get the backing of Tory MPs for House of Lords reform.
This has delayed the progress of the Electoral Registration and Administration Bill in the Lords after Lib Dem peers signalled their intention to support a Labour move to delay the review until 2018.
The government dropped the Lords vote telling peers "senior members of the government" needed to discuss the issue before peers could hold the vote.
The DUP's Sir William McCrea said the Commons should have the "earliest opportunity" to vote on the issue "if the Lib Dems are still voting against the recommended parliamentary boundary changes".
The 45-minute question session was followed by questions to Attorney General Dominic Grieve and his team of ministers.