Boris Johnson has claimed that coronavirus tends to spread “later at night after more alcohol has been consumed”.
The prime minister announced a curfew for pubs and restaurants on Tuesday which will see them forced to shut an hour early at 10pm.
Justifying his decision, he told the Commons in a statement that late night drinking seemed to have had an effect on infection rates.
Meg Hillier, Labour chairwoman of the Commons public accounts select committee, asked the why the 10pm closing time was being imposed on pubs and restaurants.
Johnson replied: "These are not easy decisions, nobody wants to be curtailing the right of restaurants and other businesses to go about their lawful business.
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"What we have seen from the evidence is that alas the spread of the disease does tend to happen later at night after more alcohol has been consumed.
"This is one way that we see of driving down the R without doing excessive economic damage and that's the balance we have to strike."
As well as the curfew, the PM also announced the introduction of tougher penalties for those who "brazenly defy" social distancing restrictions.
The penalty for failing to wear a mask or breaking the rule of six will double to £200 for a first offence and £10,000 fines will be applied to businesses breaking the rules.
He added that it is "very difficult" to ask the people of a "freedom-loving country" to obey guidelines.
Labour's Ben Bradshaw said: "Does he think that the reason Germany and Italy have far lower Covid rates than us, with life continuing more-or-less normally, might be because they have locally and publicly-run test and trace services that actually work?"
Johnson replied: "No I don't, and I think the continual attacks on local test and trace and what the NHS Test and Trace have done are undermining and unnecessary.
"And actually, there is an important difference between our country and many other countries around the world, and that is our country is a freedom-loving country.
"And if you look at the history of this country over the last 300 years, virtually every advance from free speech to democracy has come from this country and it is very difficult to ask the British population uniformly to obey... guidelines in a way that it is necessary.
"What we're saying today is that collectively, and I'm answering his question directly, collectively, the way to do this, the way to do this, is for us all to follow the guidelines, which we will strictly enforce, and get the 'R' down - that is the way forward."