What is the 'reasoned amendment' backed by rebels - and what could the government do?
There's a rebellion brewing in Sir Keir Starmer's party.
More than 120 Labour MPs have signed a "reasoned amendment" to the government's welfare policy, which will face a vote after its second reading on Tuesday.
The scale of the rebellion could signal Starmer's first Commons defeat - at the hands of his own backbenchers.
But what exactly are they asking for - and could concessions be made?
The amendment was tabled by Dame Meg Hillier, chair of the Treasury select committee, with the support of 12 other select committee chairs.
It is an attempt to force the government to water down the benefit changes, in advance of Tuesday's vote.
Signatories are calling for a delay to assess the impact of cuts to personal independence payments (PIP).
They express concerns, according to a draft seen by Sky News, about the government's own figures showing 250,000 people could be pushed into poverty, and what the forecast is for how many may find employment.
Last night, the government confirmed that talks are ongoing with backbench rebels, though ministers have continued to insist that a vote will take place on Tuesday.
There have been suggestions this morning that Number 10 is considering tabling its own amendment ahead of the vote, in an effort to avoid Starmer's first Commons defeat.
The Telegraph reports that they could promise to speed up payment of funds to help people back into work.
Another alleged option is to offer assurances that reviews of policies around welfare will be published as soon as possible.