The five-year plan would give patients to see their GP within seven days or in 24 hours if urgent care is needed.
Liberal Democrat leader Ed Davey said: ‘This Conservative government has decimated local health services and brought the NHS to its knees.
‘Patients are bearing the brunt of this failure with millions forced to wait in pain for weeks just to get a GP appointment. It is an unacceptable situation and one that is only getting worse after years of Conservative chaos and neglect.
‘The Liberal Democrats would give people a legal right to see a GP in a week or 24 hours if in urgent need, so people aren't ever left struggling to get an appointment. This is at the heart of our offer to voters at this election and our plan to fix the health and care crisis.'
The Lib Dems said their plan would be delivered by recruiting 8,000 more GPs by the end of the next Parliament who provide an extra 65m appointments a year.
House of Commons Library research, commissioned by the Liberal Democrats, shows there were 61m GP appointments with waits of over two weeks in 2023, equating to almost one in five (18%) appointments. Of these, 18m took longer than four weeks – one in 20 of all appointments.