Sir Keir Starmer has told the long-term sick to start looking for work as part of a benefits crackdown.
The Prime Minister insisted there has to be “trade-offs” between maintaining the welfare state and supporting the needy.
His comments come after he delivered his first speech as PM to the annual Labour conference in Liverpool.
The warning shot comes after his Premiership has been dogged in recent weeks over controversies over claiming freebies and the row over top aide Sue Gray’s pay.
He admitted there would be “hard cases” but the government and business must join forces to get people clocking on again.
There are 2.8 million people who are long-term sick with numbers having surged since the pandemic.
Sir Keir told the BBC: “If we want to maintain support for the welfare state, then we will legislate to stop benefit fraud, do everything we can to tackle worklessness.”
“The basic proposition that you should look for work is right. People need to look for work, but they also need support.
“That’s why I’ve gone out to look at schemes where businesses are supporting people back into work from long-term sickness.
“Quite often, I think what lies behind this is a fear for someone who’s been on long term sickness that – ‘can they get back into the workplace?
“Are they going to be able to cope? Is it all going to go hopelessly wrong?'”
Ministers realise the enormity of the problem with the bill for sickness and benefits payments set to go up by £30 billion in the next five years.
He also tackled head on the on-going criticism over axing winter fuel payments for ten million pensioners amid uncovering a £22 billion black hole when they got to office.
But he faces pressure today from the unions who will force a vote at the annual rally demanding the government u-turn on the decision.
The Prime Minister said: “economic stability is the number one, most important first step”.
“That that will only happen we deal with £22 billion pound black hole that we will. This was not on the books… I could pretend it’s not there, I could walk past it. In my view, that would risk losing control of the economy.
“By tackling it, we can commit to, among other things, the triple lock… Every pensioner will be better off under a Labour Government.”
The PM also says that he declared £20,000 in accommodation costs so his 16-year-old son could sit his GCSEs due to the attention on him at his home address during the election campaign.