Boris Johnson will unveil plans to help workers learn new skills as ministers brace themselves for a rash of redundancies this winter.
The chancellor Rishi Sunak has already warned he cannot save every job from the fallout from the coronavirus pandemic.
Tens of thousands of Britons are expected to lose their livelihoods as the government’s furlough scheme ends next month.
Mr Sunak bowed to pressure last week to announce a new, more limited, aid package to help workers, but has faced criticism the support is too little too late.
Mr Johnson will try to inject some of his trademark optimism into the bleak outlook, as he pledges guaranteed opportunities for life-long learning.
The prime minister will use a speech to set out his hopes that people can reskill at any point in their lives.
But the scheme will be open to only those without A-levels or equivalent.
He will say: “As the Chancellor has said, we cannot, alas, save every job. What we can do is give people the skills to find and create new and better jobs.
“So my message today is that at every stage of your life, this government will help you get the skills you need.”
He will add: “We’re transforming the foundations of the skills system so that everyone has the chance to train and retrain.”
Under the guarantee adults without an A-level or equivalent qualification will be offered a free, fully funded college course to provide them with “skills valued by employers”.
Ministers will set out what courses are covered at a later date, but they will be available in England from April.
The scheme will be paid for through the National Skills Fund, to which ministers will add an extra £2.5bn.
Ministers will also make higher education loans more flexible, so they can be used across a lifetime, rather than in three to four-year blocks.
