A survey for Age UK showed more than two-thirds thought the principle of forced retirement was wrong. The charity called on ministers to end "speculation and confusion" among employers and workers about the default retirement age by setting a date for the abolition of forced retirement.
Age UK said tens of thousands of workers were forced to retire last year, causing an estimated loss of 3.5 billion in economic output.
Michelle Mitchell, charity director of Age UK, said: "The default retirement age is a hugely unpopular law which is well past its sell-by date.
"Forcing people in later life out of the labour market when they want to work, save for their pensions and pay taxes is nonsense. It makes a mockery of the government's plans to help people work longer."