Rishi Sunak has unveiled a £350bn Treasury support package for businesses facing economic ruin as a result of the coronavirus crisis.
The chancellor said he was ready to do "whatever it takes" to prevent thousands of firms going to the wall as a result of the measures introduced to tackle the outbreak.
Government-backed bank loans worth £330bn will be given to companies of all sizes facing a cashflow crisis as the country goes into lockdown.
An additional £20bn-worth of business rate relief and emergency grants is also being made available to tackle the crisis.
Meanwhile, Boris Johnson said his administration "must act like any wartime government and do whatever it takes to support our economy".
Speaking in No.10 Downing Street, Sunak said: "The coronavirus pandemic is a public health emergency but it is also an economic emergency.
"We have never in peacetime faced an economic fight like this one."
He added: "The government will stand behind businesses small and large. I can announce today an unprecedented package of government-backed and guaranteed loans to support businesses to get through this.
"Today I’m making available £330bn of guarantees, equivalent to 15% of our GDP. That means any business who needs access to cash to pay their rent, their salaries, suppliers, or purchase stock will be able to access a government backed loan or credit on attractive terms.
"And if demand is greater than the initial £330bn I’m making available today, I will go further and provide as much capacity as required. I said whatever it takes and I meant it."
The stimulus is package is more than 10 times greater than the £30bn-worth of measures the chancellor announced in the Budget less than a week ago.
In addition, he said that pubs, clubs, cinemas, restaurants, theatres and other leisure venues – which the public have been urged to avoid during the coronavirus outbreak – with a rateable value of less than £51,000 will be eligible for cash grants of £25,000 to help tide them over.
And all such venues, regardless of their size, will pay no business rates for a year in an attempt to keep them afloat.
Sunak also said that individuals struggling to make ends meet as a result of the crisis will be able to claim a three-month mortgage holiday.
He added: "In the coming days I will go much further to support people’s financial security.
"In particular, I will work with trade unions and business groups to urgently develop new forms of employment support to help protect people’s jobs and their incomes through this period."
The chancellor went on: "The measures I’ve announced today are part of a comprehensive, co-oriented and coherent response to what is a serious and evolving economic situation.
"These are only the first steps. I will set out the next stage of our response in the coming days.
"We have never faced an economic fight like this one. But we are well prepared. We will get through this and we will do whatever it takes."