He was asked about a couple originally from Pakistan, granted leave to remain in the UK, who were struggling due to the coronavirus pandemic.

Stephen Timms MP told Boris Johnson: ‘They both work, they have two children.

‘The husband’s employer didn’t put him on the job retention scheme so he has zero income. His wife is still working but her income is less than their household rent. They have leave to remain in the UK but no recourse to public funds, so they can’t get any help at all.

‘Isn’t it wrong that a hard-working, law-abiding family like that is being forced by the current arrangements into destitution’

The PM replied: ‘Hang on Stephen, why aren’t they eligible for Universal Credit or Employment Support Allowance or any of the other benefits?’

Mr Timms responded: ‘That’s a very good question. It’s because they have no recourse to public funds. That’s the condition that’s attached to their leave to remain. They have been here for years; their children have been born in the UK. But because for a 10 year period they have this no recourse to public funds, at the moment they can get no help at all.’

The prime minister replied: ‘And they can’t get furloughed… obviously not. I’m going to have to come back to you on that because clearly people who have worked hard for this country, who live and work here, should have support of one kind or another. You’ve raised a very important point.

‘If the condition of their leave to remain is they should have no recourse to public funds, I will find out how many there are in that position and we will see what we can do to help them.’

Stephen Timms said that according to the Children’s Society, there are at least 100,000 children in families in exactly that position.

‘They’ve got leave to remain, they are law-abiding, they’ve got no recourse to public funds. Many of them can get no help at all at the moment,’ he said.

Many migrants with a residence permit allowing them to live in the UK are given the condition that they have ‘no recourse to public funds’. It means they are not able to claim most benefits, tax credits or housing assistance that are paid by the state.

MPs watching the questioning responded in shock to the prime minister’s response, asking why he did not seem to grasp this.

Hilary Benn tweeted: ‘Astonishing that the Prime Minister seems to have no idea what “no recourse to public funds” means.’

Jess Phillips wrote: ‘Boris Johnson not knowing what no recourse to public funds means was quite phenomenal.’

Karl Turner said: ‘The actual Prime Minister doesn’t understand how his Government policies are effective [sic] people. My colleague Stephen Timms MP asks a simple question about those that ‘have no recourse to public funds’ as a condition for them to remain. @BorisJohnson hasn’t a clue.’

Rachel Hopkins tweeted: ‘Watching PM Johnson floundering when questioned on equality impacts & women leaders’ role in Govt coronavirus recovery plans … even more excruciating than watching his apparent surprise at @stephenctimms points that many families with no recourse to public funds are struggling.’