Two-thirds said they are less likely to have their symptoms fully investigated and nearly three-quarters think they are less likely to be referred for essential treatment.

And 55 per cent said they were worried themselves about how the NHS would treat them in old age.

Age discrimination in the workplace has been illegal since 2006, but the new Equality Bill is intended to tackle more widespread forms.

The Government has said it will take around 18 months to draft regulations on how rules relating to age discrimination in health and social care should be implemented.

Alex Mair, chief executive of the BGS, said: "What this research makes clear is that the NHS is currently failing older people.

"We need to ensure that patients of all ages receive the very best care, regardless of their age."

Care services minister Phil Hope said: "The Equality Bill will allow us to end unfair age discrimination in the NHS and social care and Government is committed to making this happen as soon as possible.

"It is vital we get the legislation right to ensure there are no unintended consequences - such as service providers withdrawing beneficial age based practices. We need to bring in changes over time, to make sure we get it right."

Help the Aged's Kate Jopling, said: "The right time to pass the new age regulations is alongside the new Bill, so that older people will be protected as soon as possible.

"If this opportunity is missed older people could be left waiting indefinitely for the same protections other groups already enjoy."