Boris Johnson has announced that statutory sick pay will be available from the first day of illness under emergency legislation to tackle the coronavirus.
Under current rules workers only receive the pay, £94 a week, from the fourth day off work.
Speaking during PMQs on Wednesday, the prime minister said people who self-isolate were “helping to protect all of us by slowing the spread of the virus”.
Johnson added: “Nobody should be penalised for doing the right thing.”
But Jeremy Corbyn, the outgoing Labour leader, warned there were two million workers, “many of them women in the care sector”. who were not entitled to statutory sick pay.
“The prime minister’s statement just now is not clear whether it covers them or not, and those on social security could face sanctions if they miss appointments and therefore they and their families will face terrible hardship,” he said.