Some 300,000 more UK workers have been furloughed in the past week, raising the total to 8.7million since the start of the coronavirus crisis, latest figures show.
Around £17.5billion has so far been claimed by more than one million firms who sent their colleagues home as the country went into lockdown in March.
One in four people are now on the scheme - which is set to be wound down from August as the Government strips back its £80billion budget.
On Friday, Chancellor Rishi Sunak announced huge changes to the Job Retentions Scheme, including closing it off to new applicants from July.
He said firms will have to start paying pension and national insurance contributions from August - equivalent to around 5% per person - plus an extra 10% from September.
This will then fall to 60% in October before closing for good.
However critics have warned that with millions of people relying on it, the UK could be plunged into a bigger employment crisis than expected after it shuts down.
Labour's shadow chancellor Anneliese Dodds warned last week about job losses when the government support scheme ends.
"It is concerning that there is no commitment within these plans for support to only be scaled back in step with the removal of lockdown," she said.
Experts fear that the scheme may simply be disguising massive unemployment, with sweeping layoffs potentially on the cards after it ends.
Rishi Sunak has been clear that businesses would have to bear some of the costs and start paying national insurance contributions from August.
Staff will be able to return to work part-time without losing any furlough pay from next month, the Chancellor added.
Sunak said: "We stood behind Britain's businesses and workers as we came into this crisis, and we stand behind them as we come through the other side.
"Now, as we begin to re-open our country and kick-start our economy, these schemes will adjust to ensure those who are able to work can do so, while remaining amongst the most generous in the world."
The jobs retention scheme was introduced in March to mitigate the effects of coronavirus.
It allows employees to receive 80% of their monthly salary up to £2,500.
New figures on Tuesday also revealed that 2.5million claims totalling £7.2billion have been made under the Government scheme to support self-employed people.