It is not "constructive" to discuss any punishments that could await for Labour MPs who rebel over welfare reforms, a minister has said, as the Government looks to shore up support.
Ministers are set to lay out the concessions they will make on Monday, in the hope that the climbdown will be enough to secure backbench votes this week.
Work and Pensions Secretary Liz Kendall announced last week that changes to the personal independence payment will only apply to new claimants from November 2026, and ministers also rowed back on plans to cut the health-related element of Universal Credit after 126 Labour MPs signed an amendment that would have effectively killed the Government's Bill.
Although the changes are expected to get some of those rebels on board, there are still threats of revolt.
Baroness Jacqui Smith - who served as a chief whip under Sir Tony Blair - was asked on Sky News what the consequences should be for Labour MPs who vote against the Government on the matter.
She said: "I don't think talking about punishments, even as a former chief whip, is the constructive way forward here."
Baroness Smith later added: "It's always the case in legislation that you introduce the Bill, you have a second reading on the principles, and then you think about the detail as you take that through all of its stages in Parliament. I'm sure that that will continue to happen."
Asked on Times Radio whether rebels will have the whip removed, education minister Baroness Smith said that it is important to "keep talking" to MPs.
The legislation is due to be voted on on Tuesday at its second reading, and the Government will amend the Bill at the Commons committee stage to put the changes in place.
The original plans restricted eligibility for the personal independence payment (Pip) and cut the health-related element of universal credit.
The changes to Pip will now only apply to new claims from November 2026.
Plans to cut the health-related element of universal credit have also been altered, with all existing recipients to have their incomes protected in real terms.
Details of a review of the Pip assessment, to be led by disabilities minister Sir Stephen Timms and "co-produced" with disabled people, will also be published.
The original amendment signed by 120-plus backbenchers is expected to be withdrawn after some MPs were appeased by last week's announcement. However, a new one is expected to be tabled by rebels on Monday.
Labour MP Rachael Maskell said she would sign the new amendment aiming to stop the Bill, saying it was not clear how the promised concessions would be brought in.
"There's no confidence ... we're being asked to sign a blank cheque even with these changes,"
she told the PA news agency.
Vicky Foxcroft, who quit as a Labour whip over the reforms, told The Guardian there were "areas where I still think there's need for movement" and that she had not decided how to vote.
Olivia Blake, a Labour MP with a disclosed disability, told the paper the changes could create "an unethical two-tier system that treats two people with the exact same injury or illness differently".
Clive Efford, the MP for Eltham and Chislehurst, told BBC Radio 4's Today programme that he will still not support the Government's measures.
"There are choices that the Government can make here; there are other places it can go to identify the resources. What we want to see, and fully support, is measures the Government is putting in the palace to assist people to move into work, the right to try, we support, but we can't guarantee the savings,"
he said.
"When you're asking for £3.5 billion regardless of the impact of those changes, that can only adversely affect people who are in the benefit system."