It’s not hard to see this becoming one of several flashpoints, especially for those Labour MPs who are already anxious about the government’s direction of travel.
A handful of them raised the issue with Mahmood in the Commons on Monday – particularly the question of how children being deported alongside their parents would be treated.
This is likely to sit alongside the conversion of refugee status into a temporary status and the quadrupling of the waiting period for refugees to get permanent residence in the UK from five to 20 years as the most controversial features of Mahmood’s reforms.
This matters because the government is going to have to legislate to bring in some of the changes, and that means there will be votes in Parliament. So the extent of opposition, especially within the Labour Party, will determine whether the package becomes law.
Certainly there is tangible anxiety about this among many Labour MPs – far more than have publicly questioned Mahmood’s proposals. And those MPs who are concerned range beyond the usual critics of Sir Keir Starmer on the left of the party.
Yet it was striking in conversations with those uneasy about the government’s approach on Monday that in quite a few cases that unease was tempered by a recognition of the scale of public frustration over illegal immigration, and a belief that their constituents wanted policies like this.
There is also a minority, though a significant one, of Labour MPs who feel local pressure to speak up for the rights of asylum seekers fleeing war-torn parts of the globe.
In fact, it feels like the split on this issue within the Labour Party is less conventionally ideological and more a question of whether the challenge particular MPs are facing at the next election is likely to come from parties of the right or of the left.
It matters too that in the eyes of her colleagues Mahmood performed very, very well in the Commons on Monday, attracting genuine praise from her Labour colleagues for her ability to argue from first principles for the package while unleashing vicious put-downs on political rivals of all hues.
One of the complaints of Labour MPs about the welfare proposals on which the government was forced to backtrack earlier this year was that they were sprung on them without enough groundwork having been laid.
In this case, Mahmood has set out the arguments now but it will be some months before the first crucial votes.
That means there is a very, very long way to go and much can change. But right now, it does not quite feel like this is set to be a repeat of the welfare episode.
