Low-skilled migrants should only be allowed to come to Britain if there are no British workers who can do the jobs they want, Iain Duncan Smith has said.
The former work and pensions secretary has laid out his vision of a new immigration system post-Brexit.
The Prime Minister has asked her Cabinet ministers to come up with opportunities that Brexit can create, in each of their portfolios, this week.
Speaking to the Sunday Telegraph, Mr Duncan Smith urged the Prime Minister to limit low-skilled workers.
One suggested system for managing immigration is an Australian-style points system, but Mr Duncan Smith has proposed his own.
He said: "The question should always be asked, are there people in the UK who can do this job? You start with the premise that you want to employ people here so you need to advertise the job here."
He suggested that an existing government database, Universal Job Match, should be used to set quotas for the number of people allowed to come into the country based on the need for their skills.
Describing a potential change from EU migration rules to having more control over immigration after Brexit, he said: "It's like having the front door shut and the back door wide open ... now you get to regulate both doors and that's why the best way to do it is through a work permit process and ensuring that those that come do so after it's clear that there are no British people around that can do that job at that skill level.
"You focus more at the lower-skilled areas."