CAMPAIGNER Derek Brown fears millions of vulnerable people could become trapped in a potential nightmare as BT switches landlines to a new digital system which relies on the internet.

Retired electrical engineer Mr Brown, 71, looks after his 81-year-old wife Margaret, who has Alzheimer's, at his home in Northallerton, and is thought to be one of the first in the region to experience the new VOIP (Voice Over Internet Protocol system).

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It is being rolled out across the UK by BT over the next three years.

He does not know why they were chosen, but in October the couple received a letter informing them they were being switched to the digital voice service, and that it would not affect their call plan and contract – but it did say their old phone would stop working.

On November 7, he was told the system would be brought in the next day with the digital service taking over, and the landline no longer being usable. Mr Brown said: "I contacted BT over the internet and established they would provide two VOIP phones, free.

"They arrived the following day but until then I had to use my pay as you go mobile phone which ran out of credit on the first call.

"My wife has Alzheimer’s and telephone contact is vital should there be any domestic crisis.

"This could be a nightmare for so many vulnerable people.

"The new system is totally reliant on a fully operational modem/hub. In the event of a power cut, the phones and the modem stop working, and as we have just seen with Storm Arwen, many people have been without power for days.

"Remote ringers and adaptations to the phones also stop working. BT say battery back up packs will be provided but they would only work for up to two hours.

"New technology is being brought in with no care considerations whatsoever.

"What happens to the three million people in the UK who may not understand the changes? It is very concerning."

Mr Brown, who has campaigned to highlight problems for carers and Alzheimer's sufferers in the past, has contacted Age UK and his MP Rishi Sunak to protest over the lack of consultation, and fears about the implementation of the new system.

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A spokesperson for BT said: "We’re sorry to hear about Mr Brown’s issues during his upgrade to Digital Voice.

"We understand that this is a big change for some customers who are used to the traditional phone home service, and why we contacted all customers, including Mr Brown in October to inform them several times to advise him of the change and to contact us if he needed any additional help."

The company said it has put measures in place to ensure customers flagged as vulnerable and who do not have BT broadband are not upgraded until much later in the programme.