Britain's government has dropped plans to introduce a mainly-elected upper house of parliament, Deputy Prime Minister Nick Clegg announced on Monday, in a serious blow to the ruling coalition.
Clegg said Prime Minister David Cameron's Conservative party had failed to back the reforms of the House of Lords, and said his Liberal Democrats would now drop their support for changes to parliamentary constituencies.
"I can confirm today that we do not intend to proceed with the bill (for House of Lords reform) in this parliament," Clegg told a news conference.
"The Conservative Party is not honouring the commitment to Lords reform and as a result part of our contract has now been broken."
The move by the centrist Liberal Democrats, who formed the coalition with the centre-right Conservatives after elections in May 2010, will put severe strain on the partnership.
The Conservatives have long cherished plans to change the boundaries of parliamentary constituencies, which they have long regarded as giving them a disadvantage at the polls.
Elections are not due until 2015 but would have to be held earlier if the Conservatives lose their majority.
"Coalition works on mutual respect -- it is a reciprocal arrangement, a two-way street," Clegg said.
"So I have told the prime minister that when, in due course, parliament votes on boundary changes for the 2015 election, I will be instructing my party to oppose them."