Plans to tag elderly dementia sufferers so they can be tracked by satellite smacks of "Big Brother" and technical gimmicks, campaign groups warned yesterday.

Malcolm Wicks, Science Minister, floated the idea at a Commons committee, but insisted it should only be done with permission of the person or their family.

More than 700,000 people in the UK suffer from dementia, and by 2051 the number is expected to rise to 1.7 million.

Later government sources pointed out that Mr Wicks had been speaking in a personal capacity - the idea had not been discussed in the Department of Trade and Industry - but they were interested that campaigning groups for the elderly had not rejected the proposal out of hand.

The charity Help the Aged agreed satellite technology could have potential in helping care for those with dementia. Kate Jopling, a spokeswoman, said: "Although when we first hear this it smacks of Big Brother', we shouldn't dismiss the possibility of some new technologies to help us in providing better care for people with dementia and care that potentially allows them to stay within their communities for much longer while minimising some of the risk. "It is a real balancing act but for me the crucial issue is, is the care better for the person with dementia or is it just about our convenience? If we could use technology that is sensitive and with the consent of the families but also the individual then there may be some potential here."

Shami Chakrabarti, director of Liberty, warned against such technology replacing genuine care. She said: "A debate about better care for the elderly is a good thing but technical gimmicks often provide cheap and quick fixes rather than dignified and possibly expensive care."

A spokesman for the Alzheimer's Society said electronic tagging could ease concern for carers and give some dementia sufferers greater independence but he pointed out they needed to strike a balance between benefits and the infringement of civil liberties.

"Technology which is often used to secure animals, retail products and prisoners should not automatically be transferred to people with dementia without full consideration of the ethical issues," he said.

The National Pensioners' Convention strongly rejected the idea of tagging.

Joe Harris, general secretary, said: "Decent, free personal and nursing care should be a right of every older person and for a minister to suggest that an inhumane electronic tag on the country's most vulnerable pensioners can in any way replace dignified care is absolutely shocking."