Peers claim they are being "bullied" into accepting plans for all passport applicants to be given identity cards.
The ID card plans have "ping-ponged" between peers and MPs
Lib Dem Lord Phillips of Sudbury made the remark ahead of a vote aimed at reaching a compromise on Tuesday.
Crossbencher Lord Armstrong urged peers to back his plan to keep the scheme voluntary by allowing passport holders to "opt out" of being given ID cards
But ministers say they will already be "voluntary", because it is not compulsory to have a passport.
'Government must reciprocate'
The government's proposals, outlined in the Identity Cards Bill, have been rejected four times in Lords votes, but are backed by MPs.
Lord Phillips, the Lib Dems home affairs spokesman, said: "It is time for the government to reciprocate the Lords' willingness to compromise.
"The government must stop trying to bully the Lords and should instead listen to the merits of the argument.
"The House of Lords can be under no duty to endorse the government's breach of faith with the public, by ignoring its own manifesto and effectively making ID cards compulsory."
The bill would compel anyone getting a passport from 2008 to have an ID card and have their details added to the national identity register.
Opposition peers say cards should be voluntary, as pledged in the Labour general election manifesto.
On Sunday, Commons leader Geoff Hoon said the Lords should "accept the will of the elected chamber".
MPs voted in favour of the bill for a fourth time last Tuesday.
In theory, it could keep "ping-ponging" between the houses until an agreement is reached, or ministers could override the Lords using the Parliament Act.