LONDON—Britain is taking another small step out of lockdown as it looks nervously at a new virus surge inundating its European neighbours. With UK coronavirus vaccination rates outstripping those of European Union nations, Prime Minister Boris Johnson is easing the stark “stay at home” message that has curtailed everyday life—and kept the virus in check—for almost three months. From Monday, it will be replaced in England with a message to stay local. People will be allowed to meet in groups of six outdoors and can resume outdoor sports such as basketball, tennis, and golf. The other parts of the UK—Scotland, Wales, and Northern Ireland—are taking broadly similar steps. In Wales, thousands of people poured onto beaches and beauty spots on Saturday, after the authorities lifted travel restrictions that have been in place since December. The “stay at home” orders in Scotland and Northern Ireland are set to be lifted on April …