David Cameron is accusing Brexit campaigners of treating the potential loss of jobs and economic damage if the country votes to leave the EU as "a price worth paying".
In a speech to car workers, the Prime Minister will say key figures in the Leave campaign have conceded that withdrawal from the EU would lead to "dislocation, uncertainties and costs".
"For those who advocate leaving, lost jobs and a dented economy might be collateral damage, or a price worth paying," he is expected to say.
"For me, they're not. They never are because there's nothing more important than protecting people's financial security. That's why I believe we are better off in."
His comments were roundly rejected by the Leader of the House Chris Grayling, one of five Cabinet ministers campaigning for an "out" vote.
"That is simply not true. It is about creating the opportunity for more jobs," he told the BBC Radio 4 Today programme.
"European Union regulations cost jobs in this country. They increase costs for business. They make it less desirable to employ people in the UK."
In his speech, Mr Cameron will concentrate largely on the positive benefits of remaining in the EU and the single market.
He will say it removes barriers to trade and allows British firms to do business in the EU entirely without tariffs while being part of the "most ambitious and comprehensive" trade deals with other parts of the world.
He will also point to damage the "economic shock" of leaving would cause.
"It means pressure on the pound sterling. It means jobs being lost. It means mortgage rates might rise. It means businesses closing. It means hardworking people losing their livelihoods," he will say.