Short care visits to elderly and disabled people are "disgraceful" and on the rise, a charity has claimed.
In England, 60% of councils use 15-minute visits, which are not long enough to provide adequate care, Leonard Cheshire Disability says.
The charity says such visits can "force disabled people to choose whether to go thirsty or to go to the toilet".
The government said the Care Bill would prevent "inappropriate" short visits but would not outlaw 15-minute visits.
Leonard Cheshire wants a ban on what it calls the "scandal of flying 15-minute visits", lobbying the government to prevent the practice in England.
Care minister Norman Lamb said the government "can't ban these short visits completely" because they are useful in some circumstances, such as when a carer visits to give someone medicine.
But he told the BBC a 15-minute visit was "completely inappropriate" when people needed things like feeding or bathing.
"We're actually introducing an amendment to the Care Bill this week which will require councils to focus on an individual's wellbeing when they're organising care on their behalf, and so this sort of very short visit for personal care would not meet that standard," he said.
He also said the government plans to "force" the NHS and local government to work better together and end the "ridiculous split" between health and social care.
A report published by Leonard Cheshire said short visits "simply do not allow enough time to deliver good-quality care".
It said data from 63 local authorities pointed to a 15% rise in such visits in the last five years, and said some in councils more than 75% of care visits were carried out in less than 15 minutes.
The charity's latest research looks at England alone, but in August Unison accused many councils in Scotland of providing "care on the cheap" by arranging 15-minute home visits, and in June the union said 83% of Welsh councils were doing the same.
Research by the UK Homecare Association published last year suggested 87% of home visits in Northern Ireland lasted 30 minutes or less, the highest proportion in the UK (73% in England and 42% in both Scotland and Wales).
Separate care bills are currently going through the Scottish Parliament and the Welsh Assembly.
Chief executive Clare Pelham said visits should be at least 30 minutes long.
"It is disgraceful to force disabled people to choose whether to go thirsty or to go to the toilet by providing care visits as short as 15 minutes long," she said.
Ms Pelham said most people need 40 minutes to get up, washed, dressed and have breakfast.
"We are treating disabled and older people as if they are robots to be serviced, rather than real people who deserve to be treated with kindness and consideration," she added.
But the Association of Directors of Adult Social Services (Adass), which represents care managers, argued it was "totally wrong" to suggest all caring tasks require more than 15 minutes.
Sandie Keene, the association's president, said some short visits were "fully justified and fully adequate".
It was "frankly naive to believe that simply by abolishing 15-minute slots a magic wand will have been waved, and improvements automatically achieved in our care services," she added.
Ms Keene said social workers and their managers had to make "horrendously difficult choices" every day to give the best possible care with limited resources.
Leonard Cheshire wants peers to back a ban on short visits by amending the government's Care Bill when it is debated in the House of Lords on Wednesday.
Speaking to BBC Radio 5 live, Rosaleen, a Thames Valley care worker who gave only her first name, said 15-minute visits usually overrun.
But she said the short time available still forced carers to make choices such as whether to leave someone alone with a hot drink which they might spill on themselves, or sit with them while they drink but fail to get them ready for bed.
Asked if people's safety was being compromised by visits being too short, she replied: "Their safety, their independence, their dignity."
Another care worker told the BBC that travel time was not included in her pay, so she would work unpaid time every day travelling between appointments.
Sally Lubanov, 83, who is house-bound, said even in 30-minute visits "nothing got done" because carers would take some time booking in, checking what the previous visitor had done and preparing for whatever tasks needed doing.
She said 15-minute visits might be fine for giving someone medicine, but for people living alone it was "wonderful to see someone" and short visits allowed no time for conversation.
The Local Government Association (LGA), said social care was "substantially underfunded" and councils were under increasing pressure.
"Significant cuts to council funding mean local authorities are struggling to meet the rising demand for home care visits," said Katie Hall, chairwoman of the LGA's community and wellbeing board.
She said 15-minute visits "should never be the sole basis for care", but added: "In some circumstances such as administering medication they can be appropriate, but only as part of a wider comprehensive care plan involving longer one-to-one visits."
Leonard Cheshire Disability said a survey of 2,025 people found 93% of those who expressed an opinion agreed 15 minutes was "not long enough to support a disabled or older person to do everyday things like wash, dress and get out of bed in the morning".