Twelve of the nation's biggest unions have warned they'll fight Boris Johnson "tooth and nail" to stop any watering down of workers' rights.
The leaders of unions including Unite, Unison and the GMB sent the warning shot to the Prime Minister after his government let slip it was reviewing protections at work.
The Financial Times revealed officials are looking at the 48-hour cap on the working week and rules on factoring overtime into holiday pay as part of a post-Brexit shake-up.
Business Secretary Kwasi Kwarteng insisted rights would not be watered down - but did not deny the individual proposals and admitted a review was under way.
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