Labour has been alienated from helping the government with its Lords reform bill because of the coalition's other changes to the constitution, a leading opposition frontbencher has told politics.co.uk.
Shadow constitutional reform minister Wayne David said the switch to individual voter registration and boundary changes would hurt Labour at the next general election - and had diminished the opposition's enthusiasm for Lords reform as a result.
Labour backs the switch to an 80% elected second chamber in principle, but has effectively blocked the measure by opposing the government's timetable motion which would have secured its passage through the Commons.
That decision raised the possibility of a massive rebellion by Tory backbenchers, which would have resulted in defeat for the government had Commons business managers pressed the motion to a vote.
"The government does not see constitutional change in a consensual way," David said.
"They say it is a political process which will often be skewed for political advantage. That's no way to go about constitutional change in a democracy. It is not in the country's advantage for constitutional change to be a political football."
Conservative and Liberal Democrat ministers' constitutional reforms have been criticised from the start, as the Fixed Term Parliament Act deliberately linked the establishment of a five-year electoral cycle with the mechanics setting up the 2011 electoral reform referendum. Both were judged by critics to be permanent constitutional changes introduced to suit the needs of the government of the day.
Further reforms are being pushed through which are expected will adversely affect Labour. Boundary changes and the reduction in the number of MPs from 650 to 600 will see the Conservatives gain at least 20 more seats in parliament. The switch to individual electoral registration will see many inner-city voters - mostly Labour supporters - fall off the register for the 2015 election altogether.
"This is not the Labour party moaning and groaning," David added.
"It's perceived as advantage. What we want to see is a system which his fair to everyone and accepted by everyone, which has always been the case with boundary changes in the past."
The Commons and Lords must both approve boundary changes for them to go ahead. Labour expects the government to use its power of patronage to win over MPs expected to lose their seats, but many backbenchers of all parties could rebel if they find their careers endangered.
David admitted that Labour is "on the sidelines" and that Liberal Democrats, also set to lose out, will prove critical.
"I can quite understand how the Liberal Democrats feel because these changes would impact them adversely," he said.
"The Conservatives have placed a big emphasis on these boundary changes, primarily because this is to their political advantage."
Ministers have repeatedly denied claims that the coalition's constitutional reforms are biased in their favour.
Liberal Democrats have publicly threatened to withdraw their support for boundary changes if Lords reform does not go ahead, however. Tories say the redrawing of Britain's electoral map was originally a quid pro quo for the alternative vote referendum.