Boris Johnson is facing his biggest backbench rebellion since the 2019 general election when MPs vote on new Covid rules for England later.
Around 70 Conservatives are expected to vote against plans to introduce mandatory Covid passes to enter large venues such as nightclubs.
The PM calls them a sensible response to rising Omicron cases – but the plan has sparked civil liberties concerns.
The measure is still likely to pass, as Labour plans to vote for them.
It would mean that from Wednesday, people will have to prove they are fully vaccinated or have a negative lateral flow test to enter large venues.
In a series of votes in the House of Commons on Tuesday afternoon, MPs will also vote on:
Deputy Prime Minister Dominic Raab told the BBC he hoped the measures would mean “we go into this Christmas in a very different position to last year” and “people can feel reassured” about the their festive plans.
He added that the new Covid passes were not “an unreasonable thing” to ask of people to enter large venues, adding: “I would do it voluntarily.”
‘Balanced and proportionate’
The Covid pass measure has proved controversial on the government’s own benches, with one Conservative MP, Marcus Fysh, telling the BBC it was “the thin end of an authoritarian wedge”.
Another Conservative, Andrea Leadsom, said one of her constituents was now “now less afraid of Covid than she is of intrusive and incoherent government regulations”.
Mr Johnson sought to reassure his colleagues, describing the measures as “balanced and proportionate”, but added there was “no room for complacency”.
The BBC estimates around 70 Conservative MPs are expected to vote against the introduction of Covid passes, which would be the biggest backbench rebellion against the prime minister since he won a Commons majority at the 2019 election.
Tory rebellions on the other measures are likely to be smaller.