The Tories are protesting that stripping the Lords of hereditary peers will create the biggest quango in Britain, with life peers appointed by the Prime Minister's patronage.
He said the Tories could amend not only Lords Reform Bill, but a number of other Bills "and use powers rather more thoroughly than we do at the moment" without breaking any conventions.
"The Government might find its legislative programme may be in even greater trouble next session than it is in this one," he warned.
"The Government is reinforcing the impression that they haven't a clue what to do and that they are trying to blow a lot of smoke into all our faces rather than treating the matter with the seriousness it deserves."
Lord Cranborne, who is a hereditary peer, went on: "I am genuinely not prepared to die in a ditch for the hereditary peerage. The real point is what is going to be an effective second chamber.
"We should not get hung up on the idea of defending the hereditary system as a condition for reform."
And he stressed: "This is not just a high Tory last-ditch stand. I am constantly reassured by the number of Labour peers who come and tell me we are on the right lines."
Lord Richard, Leader of the House of Lords, said later: "The Government has a clear mandate for the reform of the House of Lords, starting with removing the sitting and voting rights of hereditary peers.
"Once more the Opposition are playing games, as they have been doing for months.
"Now they are threatening to frustrate the reform endorsed resoundingly by the electorate."Reuse content