Jeremy Corbyn and John Healey

A Labour government would rip up the government’s definition of affordable housing and instead bring in a measure linked to people’s incomes, Jeremy Corbyn will say on Thursday.

A report, Housing for the Many, accuses ministers of stretching the term affordable to breaking point to include homes let at up to 80% of market rents – more than £1,500 a month in some areas – and homes for sale up to £450,000. “It has become a deliberately malleable phrase, used to cover up a shift in government policy towards increasingly expensive and insecure homes,” it says.

The Labour leader and John Healey, the shadow housing secretary, set out the party’s plans to link affordability to people’s incomes on tenures including social rent, living rent and low-cost ownership, in the 40-page green paper, to be launched on Thursday.

Labour says one “common yardstick” is whether rent or a mortgage costs more than one-third of a household’s after-tax income.

The green paper says Labour is keen to help not just the poorest in society, but also “the ‘just coping’ class in Britain today who do the jobs we all rely on – IT workers, HGV drivers, joiners, warehouse managers, lab technicians, nurses, teaching assistants,…