U.K. Prime Minister Theresa May’s director of strategy has resigned, leaving the British government without the authors of her Brexit vision at a critical time in negotiations with the European Union. 
Chris Wilkins will leave his post inside May’s office in 10 Downing Street at the end of this week, he said by telephone on Wednesday.
The departure means that May has lost both her top strategists in the wake of last month’s general election. Nick Timothy, her co-chief of staff, quit the day after May’s Conservatives were stripped of their parliamentary majority in the poll. He and Wilkins wrote the Brexit speech in January in which she set out her plan to take the U.K. out of the single market and customs union.
Wilkins, who informed May of his decision last week, before she went on vacation, said he intends to work in the private sector as a communications consultant.
“I always planned to …