Campaigners have called for them to be scrapped, saying the Home Office’s attempts to create a “hostile environment” for illegal migrants is now hitting Britons and others who have the right to be in the UK.
There was outrage after it emerged members of the so-called “Windrush generation” – who came here before 1973 and have the right to remain in the UK – were being told to leave.
The resulting uproar led to the then home secretary Amber Rudd resigning.
Her successor Sajid Javid has promised a new and more compassionate system. But the Prime Minister made clear that current measures are here to stay.
The key was to ensure those in the UK legally did not get caught up in them, she said.
Asked about calls to scale back schemes like “right to rent” or those which force hospitals to charge people who don’t live in the UK for medical treatment, Mrs May insisted that they had the backing of taxpayers.
She said: “If you talk to members of the public, what they want to know is that we are dealing with people who come to the UK illegally.
“And that’s why it is important we are able to continue to take measures to identify and do just that.”
Asked if there should be any changes, she replied: “We do need to ensure… we don’t see people caught up in that who are British.”
Earlier this year the Health Secretary Jeremy Hunt launched a crackdown on so-called “health tourism”, thought to cost the UK tens of millions of pounds every year.