Rishi Sunak has been told he has just 24 hours to change course on the Government's furlough scheme or risk making an "historic mistake".
Labour warned the Chancellor that jobs could be lost if he does not abandon his "one-size-fits-all" withdrawal of support.
From August 1 employers will have to pay National Insurance and pension contributions for their staff.
And in September, companies will have to pay 10 per cent of furloughed employees' salaries - rising to 20 per cent in October.
Shadow chancellor Anneliese Dodds said the move could lead to a "python-like" squeeze on jobs in some of the sectors that have been hardest hit by the coronavirus pandemic.