Carphone Warehouse, a UK chain of communications stores, refuses to sell Internet services or other contract-based plans to people over 70 unless they are accompanied by a young person. They say that septugenarians are too old to understand the terms of telecoms contracts.
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."
(Thanks, Miss Cellania!)