The head of the IMO's GP committee says the UK's approach to its so-called 'Freedom Day' is arrogant and dangerous.
Dr Denis McCauley was speaking as most of the mandatory lockdown restrictions in England have been lifted, like social distancing and mask wearing.
It also means venues such as nightclubs can re-open.
Critics of the British government's approach have accused ministers there of being reckless in going ahead, in the face of daily case numbers hitting their highest level in six months and the continuing spread of the Delta variant.
But proponents argue the success of the UK vaccine rollout means hospitalisations and deaths will be lower than in previous waves.
But Dr McCauley told Pat Kenny this will see deaths rise.
"I think the sort of 'let it burn' policy is a little bit arrogant, there's a significant risk associated with that.
"Even as we see in Ireland... we have an increase of 30% in our numbers at least over the last week.
"We're seeing people going into hospital - now the transference isn't the same as it was in January, but that still means that ICU bed usage in Ireland has gone from 13 to 20.
"That will get worse - but when you transfer it back to the UK, that is going to mean an awful lot of deaths.
"An awful lot of people in ICU with secondary long-term issues.
"As a national policy it's one that I would cringe at: I think it's a very dangerous policy".
He also says high rates of COVID-19 infections seen in north Donegal - around 600 per 100,000 - could potentially happen elsewhere "if things are not managed well".
While Dr McCauley says he believes antigen tests will be used here in the medium-term.
"Lateral flow tests have a place and it's just defining what the place is.
"I think... in an outbreak situation and in a serial testing situation, they have a place.
"Their efficiency at a restaurant will screen out probably the very symptomatic people, it will also screen out half of the asymptomatic people.
"Has it a place? Yes. Where is that place? I'm not sure yet.
"It's a useful test, but is it the gold standard that will make the restaurant or the plane completely without people who have symptomatic COVID? I don't visualise it as that.
"It's now adding an extra layer of comfort if you're giving antigen tests.
"And I think it will be used in the medium-term".
