Ball in Your Court, Weakened May Tells EU on Brexit Talks

British Prime Minister Theresa May delivers her keynote speech to delegates and party members on the last day of the Conservative Party Conference at Manchester Central on Oct. 4, 2017 in Manchester. Carl Court/Getty Images

LONDON—British Prime Minister Theresa May will tell the European Union on Monday the “ball is in their court” in Brexit talks, trying to advance negotiations despite a party conference that left her weaker than ever.