Sorry, you can't have the internet... you're over 70

But the young man behind the counter had other ideas. He said she was barred - because she was too old.

The 75-year-old would only be allowed to sign the forms for the Carphone Warehouse's TalkTalk phone and broadband package if she was accompanied by a younger member of her family who could explain the small print to her.

Mrs Greening-Jackson, who sits on the board of several charities, said: "I was absolutely furious. The young man said, 'Sorry, you're over 70. It's company policy. We don't sign anyone up who is over 70.'

"Later a young lady said company policy is that anyone over 70 might not understand the contract. She said, 'If you would be prepared to go to the shop in town and take a younger member of your family we might give you a contract.'

"I have just completed a visa form to go to Russia. Last year we did one for walking the Wall in China and here is this person saying I would not be able to understand a basic form - and it was basic. It is pure ageism.

"Somebody has decided when you turn 70 you lose a lot of your mind. I find this is ridiculous."

When her case came to light on Radio 4's You And Yours last week, Carphone Warehouse admitted it had adopted an over-70 rule.

But the firm insisted it was not a blanket policy and claimed the guidance was to protect the elderly. A spokeswoman said: "It is not our policy to refuse business from adult customers of any age group. However, we do ask our agents to use their discretion when dealing with older customers."

She added that the discretionary rule had been introduced in response to complaints that staff had mis-sold products last year.

Liberal Democrat MP Paul Burstow, who chairs the all-party parliamentary group on older people, described the practice as 'deeply offensive'.

He said: "It is nonsense to assume those over the age of 70 cannot understand this sort of package, especially with the huge explosion of 'silver surfers' using the net."

New laws next month will outlaw ageism in the workplace. But Help the Aged wants the rules extended to protect consumers. "We see companies putting in place arbitrary age rules all the time,' a spokeswoman said. "To deny people services because of their age is just crazy. There needs to be legislation to address this."