PARIS—The father of British Prime Minister Boris Johnson said on Thursday he was in the process of applying for a French passport to maintain his ties with the European Union after Brexit. Stanley Johnson, a former member of the European Parliament who voted Remain in Britain’s 2016 referendum, told RTL radio he wanted to become a French citizen because of strong family links to France. “If I understand it correctly, I am French. My mother was born in France, her mother was totally French as was her grandfather. So for me it is about reclaiming what I already have. And that makes me very happy,” said the 80-year-old Johnson, who was speaking in French. “I will always be a European, that’s for sure. One cannot tell the British people: you are not Europeans. Having a tie with the European Union is important,” he added. His son Boris was the public …