Plans to reform the Lords were in the Queen's Speech
Labour MPs are set to oppose parts of the government's plans for political reform outlined in the Queen's Speech which they say are a "stitch-up".
Aspects of plans for five-year fixed-term parliaments and for fewer MPs are "completely wrong", said acting Labour leader Harriet Harman.
And there are concerns about reported plans to increase the number of Conservative and Lib Dem peers.
The government says its parliamentary reform bills will "redistribute power".
The coalition government unveiled plans for several parliamentary reform bills in the Queen's Speech, which include proposals for five-year fixed term parliaments, which would mean the next UK general election would be held on 7 May 2015.
They also allow for a referendum on changing the voting system from first-past-the-post to the Alternative Vote - in which candidates are ranked in order of preference and win once they have 50% of the vote - although no date for a referendum has been set.
There are plans for people to get the "right of recall" for MPs "judged to have engaged in serious wrongdoing". They would be able to force a by-election if they can get 10% of electors to sign a petition.
And there are proposals to ask the Boundary Commission to draw up plans for more equal sized constituencies, with fewer MPs, ahead of the next election - something seen to favour the Conservatives and opposed by Labour MPs.
The government said the bills will "transform politics" and give people a greater say over how they are represented, give parliament more control over the government and improve Parliament's reputation.
But concerns have been raised about the fixed-term parliament legislation which would give MPs the power to dissolve Parliament early - a power currently held by the prime minister - but only if 55% voted to do so.
The figure is high enough to stop the Conservatives on their own trying to force an early election - or the Lib Dems leaving the coalition and siding with opposition parties to dissolve parliament before the fixed term is up.
A government can lose a confidence vote on a simple majority of MPs - which would usually result in the prime minister asking the Queen to dissolve Parliament.
Critics say the new power could lead to a "zombie government" which only enjoyed the support of 45% of the House of Commons and was unable to get its legislation through.
Labour MP Angela Eagle denounced it as a "stitch-up". Former Foreign Secretary David Miliband told the BBC it invented "a magic constitutional rule to protect David Cameron's back and Nick Clegg's back".
And acting Labour leader Harriet Harman told MPs the move was a "political pre-nup" for when the coalition partners "shrink back from their loveless embrace".
She added it would "allow the government to cling on to office having lost the support of the House" and said Labour would argue that the fixed term should be for four years, not five.
But Conservative Cabinet Office minister Mark Harper, who has been working on the legislation, told the BBC: "There are no changes at all to the no confidence proposals, a government could still be defeated by 50% plus one.
"That government would have then to resign, you just wouldn't automatically get - indeed you don't now - automatically get a dissolution.
"Her Majesty the Queen would see if there was an alternative government that could be formed and that's actually what happens now. What we're doing is removing the prime minister's power to kick out Parliament and have another election - he's giving up power, not taking it."
After several complaints from Labour MPs during the Queen's Speech debate, Prime Minister David Cameron said Labour had campaigned for fixed term parliaments during the election.
He said: "If you have a fixed term parliament, you have to have some way of trying to make sure it is a fixed term parliament. That's why [Labour MPs] voted to support a 66% threshold for the Scottish Parliament."
Ms Harman also criticised plans to reduce the number of MPs and make sure that their constituencies all contain roughly the same number of voters by redrawing boundaries.
"It would be morally unacceptable for seats to be cut and boundaries to be redrawn on the basis an electoral register from which three and a half million people are missing," she said.
Former minister Margaret Hodge told the BBC she supported reform of the House of Lords but was concerned about the coalition's agreement to create new peers "with the objective of creating a second chamber that is reflective of the share of the vote" at the general election.
There are currently 211 Labour peers, 186 Tory peers, 72 Lib Dem peers, 186 crossbenchers and 52 others.
"I don't think it's a good portent if the first acts that they do is to actually rig the House of Lords as a revising chamber by putting in 100 new peers," she said.
But former Lib Dem leader Sir Menzies Campbell told the BBC: "The House of Lords is rigged at the moment for heaven's sake. It doesn't reflect the balance of opinion in the country."
And Mr Cameron said former Labour PM Tony Blair had "appointed more peers than any prime minister in British history".