People will be also expected to put the value of their property towards home care costs for the first time, with the state stepping in to pay when someone has less than £100,000 in assets.
The measures will be contained in the Conservative election manifesto, which will also include plans to double the charge for employers to bring in skilled workers from outside the European Union, and the scrapping of universal free school meals for infants to pay for free breakfasts for all primary children.
May is expected to ditch the 2015 pledges on the pensions triple lock and the “tax lock” – which guaranteed that none of income tax, VAT or national insurance would go up – and will also lay out changed fiscal rules to give the Government more time to clear the deficit.
In an article for The Sun, the Conservative leader dedicated the manifesto to “ordinary working families” and, after pre-announced plans for a cap on energy bills, hinted at further market interventions.
“I am determined to cut the cost of living for ordinary working families, keep taxes low and to intervene when markets are not working as they should,” she wrote.
“You are the people who work hard every day and make this country what it is.”
The Sun reports that rail ticketing, landlord agreements and mobile phone deals will all be simplified to help consumers.
The Labour party has accused the Tories of “a track record of failure and broken promises” ahead of the launch.
At the moment, all pensioners receive up to £300 a year to pay for their winter fuel bills. Under the Tory plans, that will only be available for the poorest OAPs.
The manifesto will say that people with cash and assets worth less than £100,000 will not have to contribute to their care costs, up from the previous threshold of £23,250.
However, those receiving care in their own homes will have the value of their property count towards that figure for the first time – something that previously applied only to those in residential care.
Health secretary Jeremy Hunt told the BBC the changes would "give security to every family in the country".
"It’s a big step forward but we’re being honest about the trade-offs," he added.
Nobody would have to sell their house while they or a surviving spouse was still alive in order to pay for care, the manifesto will say.
There will also be no cap on the overall costs of care – scrapping one of the recommendations of the Dilnot Commission which was set up under the Tory/Lib Dem coalition. According to The Times, that move would save approximately £1.3bn.
The Liberal Democrats have branded Mrs May the “lunch snatcher” after her plan to end another coalition policy, the introduction of universal free school lunches for all infants.
Those will be replaced by a commitment to free breakfasts for all at primary schools, with the money saved contributing to a £4bn increase in school funding.
The Prime Minister will say that will make sure no school loses out in cash terms through the proposed new school funding formula, which is designed to equalise the allocation of resources around the country.
A Conservative spokesman said: “We have protected and increased school funding to the highest level on record but we accept there is more we can do.
“This extra money means no child will lose out. The choice at this election is between Theresa May, offering strong and stable leadership and more money for schools, or a shambolic Jeremy Corbyn whose sums don’t add up and whose nonsensical economic ideas would mean less money for schools.”
This will be the third consecutive Conservative manifesto that sets a target to lower net migration to less than 100,000 per year.
According to the BBC, it will commit to “bear down on immigration from outside the EU” through every entrance scheme.
One policy will be to double the recently-introduced Immigration Skills Charge, which requires firms to pay £1,000 per year if they want to bring in a skilled employee from outside the European Union.
May is also expected to set out plans to make immigrants pay more for the NHS.