British Prime Minister Boris Johnson has rejected the Scottish and Welsh governments’ call for a further toughening of travel restrictions following the discovery of cases of the Omicron COVID-19 variant in the UK. Five cases of the new variant have been detected in England, and six cases have been identified in Scotland. The UK government has put in place new travel restrictions, requiring passengers coming into the UK to do a PCR test two days after arrival. But Scottish First Minister Nicola Sturgeon and her Welsh counterpart Mark Drakeford wrote to the prime minister, calling for people coming into the UK from overseas to be required to self-isolate for eight days and then do a second PCR test. “Public health advice is unequivocal that this is the best and safest way to protect against the importation of this variant to the fullest extent possible,” they said. But Downing Street rejected …