Labour’s Yvette Cooper, who chairs the Home Affairs Committee, raised concerns over images of busy queues at Heathrow Airport last week.
She said: “Can [Priti Patel] tell me why we saw crowded scenes at Heathrow on Friday at the UK border, the very opposite of quarantine?
“Is it true that for months people had been waiting for hours in those queues in unsafe circumstances and is it true that the Border Force lifted some of the checks that she just said were being applied to 100% of passengers because those queues were unsafe?”
Ms Patel responded: “The fact of the matter is those queues materialised because of the compliance checks that Border Force had put in place.
“I do want to emphasise, and I’d like to thank Heathrow Airport because [Ms Cooper] will also be aware that colleagues in Border Force work with the airport operators in terms of social distancing measures at the airport.
“That is a joint piece of work that takes place and all airports take responsibility for their work in how they manage their own flows and Border Force in particular are there to enforce the checks and as they are doing now achieving 100% coverage.”
A Conservative MP has asked the government to publish its criteria for deciding which border control measures will be in place at any time and why.
Nigel Mills (Amber Valley) told the Commons: “I can welcome these proposed measures, clearly at times of highest risk we need the strongest measures.
“But would she agree to be transparent and publish the criteria the government will use for deciding what measures will be in place at what time between quarantine, self-isolation or travel corridors being allowed?”
Priti Patel said: “There are processes around making decisions and clearly when changes come forward the government will absolutely announce those and the details of them in due course.”
Meanwhile, Conservative Sir Desmond Swayne (New Forest West) asked: “Is it usual for prisoners to be billed for the cost of their incarceration?”
Ms Patel referred him to her earlier statement.