The new rules, which began at 04:00 GMT on Sunday, follow a ban on non-UK citizens coming to the UK from Denmark.
At the weekend, one of the big testing firms said Covid tests for travellers arriving in the UK should be scrapped. Simon Worrell, global medical director of Collinson - which also runs airport lounges - said: "As soon as we can drop it, we will be delighted."
That tweet, and another from the company's global head of communications, prompted some lively replies, including that Bobby Axelrod, the rapacious hedge fund boss in Billions (played by Damian Lewis) should short Peloton shares - a bet the price will fall.
In New York City this fall, thousands marched against state requirements for healthcare workers, teachers and government employees. The city, which has since expanded the rule to private employers, ultimately put 9,000 city workers on leave as the mandate kicked in,...