The former prime minister said his proposed changes - which would make it harder for alleged victims to remain in the UK - could be exploited by criminal gangs.That would force those claiming to be modern slaves to provide more evidence to prove they are not making bogus allegations.“For the first time, we will actually require a case worker to have objective evidence of modern slavery rather than just a suspicion.”Sunak made the announcement as part of moves to crack down on illegal immigration.“If you’re somebody who’s been trafficked here as a sex slave, and you manage to find your way out of that and look to somebody for help, the chances are you probably haven’t got a piece of paper or a written statement from somebody to say ‘you’ve been in slavery’.So it’s making sure that, in dealing with problems that are identified we don’t create other problems.”Elsewhere in the interview, May said Sunak had made good progress in restoring the Tories’ reputation following Liz Truss’s disastrous time as PM."