Wetherspoons customers in the southern areas of the country which are entering Tier 3 on Wednesday will be able to have a real ales pint for just 99p until then.
The nation-wide company said it will slash the price as any unsold beer in areas moving to Tier 3 would be thrown out anyway.
It comes after Health Secretary Matt Hancock announced the the whole of London and parts of Essex and Hertfordshire will be facing the strictest measures to curtail the spread of coronavirus.
He announced the change as MPs warned coronavirus numbers in London were “off the charts” and a new strain of the virus which spreads more rapidly was identified in the south.
Wetherspoon spokesman Eddie Gershon said: “We would have to throw any unsold real ale away in those pubs moving to Tier 3, so it makes sense that our customers can enjoy it at even greater value prices than normal in those pubs that will be affected.”
Once the tightened restrictions come into effect at 12am on Wednesday, pubs under Tier 3 must remain closed except for takeaway, drive-through and delivery only.
The chain’s chairman Tim Martin, a vocal critic of the measures, told talkRadio on Monday the decision amounted to a “lockdown by any other name”.
He said: “It’s very sad.
“I think it’s possibly over 650,000 people in pubs and the hospitality industry alone out of work – that’s probably the working population of say Liverpool and Manchester, the equivalent, and for no health benefit – not that I can see.”
The British Beer & Pub Association said 56,000 jobs in the sector are now at risk in London alone, with all of the capital’s 3,680 pubs forced to close except for takeaways.
Earlier this month, Mr Martin said he would keep eight of his pubs open in Wales, effectively trading as cafes in Cardiff, Newport, Caernarfon, Cwmbran, Mold and Wrexham, after the Welsh Government barred the sale of alcohol in hospitality venues.
Meanwhile, celebrity landlord Tom Kerridge backed the Pub Matters campaign, which calls on the government to allow for pubs to stay open or risk losing them forever.
The campaign was launched by an industry coalition including Campaign for Real Ale, the British Beer and Pub Association and the British Institute of Innkeeping.
The movement aims to keep pubs open regardless of the tier there in amid fears further closures would force them to shut indefinitely.
The calls come amid estimates of 2,500 pubs having to shut this year – double the number of closures last year.
Mr Kerridge issued a stark warning on the future of pubs as he said: “Without greater Government support our unique pub culture will be under significant threat – and we will see many pubs close their doors forever.”