Britain's most vulnerable dementia sufferers are to be given protection against telephone scams under a new scheme to be announced by Theresa May.
Call-blocking devices will be installed on phones to prevent conmen getting through.
The Government will say in an announcement on Thursday that it will spend an initial £300,000 on the technology, which will protect 1,500 people.
It comes two years after George Osborne set aside £3.5 million to trial call-blocking technology to protect pensioners who are frightened to pick up their phone for fear of being scammed.
We have seen people tricked out of thousands of pounds by scam callers and this government is determined to clamp down on their activities once and for all
The TrueCall devices require callers to enter a PIN code before they are connected, meaning recorded messages, silent calls and scam calls are all blocked.
Mrs May said: "We want to create a fairer society by cracking down on unscrupulous practices which target the most vulnerable.
“We have seen people tricked out of thousands of pounds by scam callers and this government is determined to clamp down on their activities once and for all."
The Alzheimer's Society believes 15 per cent of all dementia sufferers have been the victims of financial sharp practice such as cold calling or mis-selling.
Richard Lloyd, the head of the Government’s former nuisance call taskforce, said: “This is a good first step. “It’s exactly the kind of extra protection vulnerable people need from nuisance calls.
“The Government should offer this help to many more elderly people who are at home all day and are at risk of harassment or scams.”
A Downing Street spokesman said the initial 1,500 people able to receive the devices would be identified by doctors, Trading Standards teams and councils.
The devices can either ask callers to enter a PIN code or divert calls to a friend or relative. A similar scheme run by National Trading Standards last year resulted in 93 per cent of participants feeling safer.
The Government is due to enact plans to hit company bosses and firms with fines up to £1 million if they breach the Privacy and Electronic Communications Regulations.