Dementia is such "a horrible condition" it has become the disease that most frightens people over the age of 55, the Health Secretary told Good Morning Britain.
Speaking ahead of a conference on dementia, Jeremy Hunt reiterated the Prime Minister's pledge to find a cure for the disease "by 2025" and remained optimistic it could be beaten.
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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.