Former Prime Minister Gordon Brown says the government must “spend now to save later” to save the economy.
The ex-Labour leader has been promoting his campaign to stop the coronavirus pandemic leading to mass unemployment.
It comes as MPs called on the government to consider a targeted extension of its furlough scheme which ends on October 31.
The former Chancellor told Good Morning Britain: “We need now a recovery plan, we need to avoid a cliff edge on October 31. The health successes have been too few for us to be able to say that the lockdown is completely over for everyone.
“And therefore we need new measures. I don’t think the government’s plan is up to it.”
He said the government should extend the furlough scheme part-time in some sectors perhaps linked to some training programmes.
Mr Brown said if it gets to the stage where three million people are unemployed: “We are facing long term damage, losing skills, losing capacity. We cannot afford not to spend now to save later.”
The Treasury Select Committee today warned that the coronavirus crisis risks mass long-term unemployment and viable firms could go under without support.
The committee chairman and Tory MP Mel Stride said: “The Chancellor should carefully consider targeted extensions to the Coronavirus Job Retention Scheme and explain his conclusions.
“The key will be assisting those businesses who, with additional support, can come through the crisis as sustainable enterprises, rather than focusing on those that will unfortunately just not be viable in the changed post-crisis economy.”
He urged the Chancellor to continue to “show flexibility” in his approach.
Mr Sunak has ruled out an extension, saying that firms will be given £1,000 for every furloughed worker still in employment at the end of January.
Under the government’s Coronavirus Job Retention Scheme workers placed on leave received 80 per cent of their pay up to a maximum of £2,500 a month.