The five biggest business groups in the UK have written an open letter calling for urgent changes to the government's Employment Rights Bill.
The proposed new law, due to be scrutinised by the House of Lords this month, includes a right to guaranteed hours and cracks down on zero-hour contracts without the offer of work.
But the British Chambers of Commerce, Confederation of British Industry, Institute of Directors, Federation of Small Businesses and Make UK warn the Bill in its current form could hit growth at an uncertain time for the UK economy.
The government insists the Bill will deliver the "biggest upgrade to workers' rights in a generation".