Liberal Democratic and Labor members of Parliament voted to delay a review of constituency lines until after the 2015 General Election, The Guardian reported. The postponement passed 334-292.
The House of Commons currently has 650 members, which Prime Minister David Cameron would like to reduce to 600. The Conservatives currently hold 303 seats and the Liberal Democrats 57, giving the coalition an overall majority.
The Conservatives might have an easier time winning a majority in 2015 with a smaller Parliament.
Deputy Prime Minister Nick Clegg, the Liberal Democratic leader, has said the party's decision to break with Cameron on constituency boundaries followed the failure of an effort to make the upper chamber, the House of Lords, an elective body with members serving 15-year terms. Cameron was unable to muster the votes within his party for the change.
Penny Mordaunt, a conservative MP, accused Clegg and the Liberal Democrats of hoping to become part of a coalition with the Labor Party after the 2015 election.
"The Liberals have exchanged their legendary sandals for flip-flops in the hope that it will enable them to keep their options open," she said.