Boris Johnson took office as British prime ministeron Wednesday after an audience with Queen Elizabeth, a moment that put anavowed Brexiteer in control of Britain`s exit from the European Union for the firsttime since the shock 2016 referendum.

Johnson enters Downing Street at one of the most perilousjunctures in post-World War Two British history - the United Kingdom is dividedover its divorce from the EU and weakened by the three-year political crisisthat has gripped it since that referendum.

One of Britain`s most prominent Brexit campaigners, Johnsonhas repeatedly pledged to leave the European Union by Oct. 31 - "do ordie" - and to inject a new optimism and energy into the divorce, which heargues will bring a host of opportunities. But his Brexit strategy sets theUnited Kingdom up for a showdown with the European Union and thrusts it towardsa potential constitutional crisis, or an election, at home.