It should be the responsibility of care providers to report neglect of older people to social services, Stephen Lowe of Age UK has told ITV News.
"It's down to services to make people feel confident that they won't face reprisals," he said.
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The letter was signed by the CBI, British Chambers of Commerce, the EEF, the Institute of Directors and the Federation of Small Businesses.
A spokesperson said Rory Stewart's remarks were in line with the British government’s stated position.
The minister's intervention will come a week after Trump decertified the landmark agreement claiming it was not in the US national interest.