Some companies are refusing to pay staff for time they spend travelling between patients' homes, says care services minister

Companies that dodge paying carers the minimum wage will be "named and shamed" as a minister warned that the next big health scandal would "almost certainly be" in care and support services.

In a speech in London, Norman Lamb, the care services minister, said he had been told of companies refusing to pay workers for the time they spend shuttling between homes. "If you don't pay your staff properly then the risk of poor care cannot be far behind," he said.

"There have been several reports about rushed 15-minute visits for personal care and a lack of basic human kindness and support. I have also spoken to home care workers who have told me that they are themselves concerned about falling standards."

Lamb said he would be writing to the Department for Business, Innovation and Skills to "ask for those providers to be named and shamed for their non-compliance. There is no excuse for breaking the law … In some cases, those employers are experts at covering their tracks. We all need to do all we can to uncover them."

The scandal of unpaid workers in the care industry affects tens of thousands of workers. A study by academics at King's College London in 2011 estimated that there are between 150,000 and 220,000 care workers in this position.

Gavin Kelly of the Resolution Foundation told the Guardian: "Norman Lamb deserves real credit for highlighting the scandalous treatment of a large number of care workers who are getting ripped off as a result of them not being paid for their travel time which is a key element of their job."

"This practice needs to be stamped out once and for all. Rather than just relying on 'naming and shaming' the culprits we need to see proper enforcement of the law and prosecutions of anyone who is found to be breaching the minimum wage regulations."

Kelly also pointed out that unlike the furore over unpaid graduate internships, the care workforce – 80% female, low-skilled, lightly unionised at the bottom end, and with a high proportion of migrant workers – gets little coverage. "It's hard not to think that if similar practices were being used in other higher-profile sectors there would be much more of a public outcry."

The health minister pointed out that the healthcare regulator, the Care Quality Commission (CQC), had warned in February that a quarter of agencies providing care to people in their own homes do not meet all five national standards of quality and safety.

"You'd be blind not to see that the next big scandal will be in care and support services. That's why we need to be completely vigilant."

Lamb said the Francis report into the scandal of poor care and "excess" deaths at Mid Staffs hospital would lead to "minimum training standards" for staff, which would be enforced through the CQC.

However, he said that registering the 1.5 million people who work in the industry – mainly helping elderly people with getting into and out of bed, washing, dressing and eating – "would end up in a bureaucratic nightmare".

"Remember in Mid Staffs all the nurses were registered and we watched the Nursing and Midwifery Council struggle with coping with the fallout [of the scandal]," he said.

Instead he said he would hold a meeting with industry to "transform home care services into the future". Lamb said too many services were driven by cost concerns, with shrinking time slots for vulnerable people as money becomes tight.

He pointed out that NHS Choices, the website run by the health service, would be transforming itself with Tripadvisor-style reviews of services and he would be encouraging local authorities to commission services "to actually support people, rather than just checking them off their list of 15-minute slots".

• This story was updated on 17 April 2013 to include commentary that was inadvertently omitted in the editing process.