Theresa May Vows to Unify Britain Behind EU Exit

"Remain" supporters demonstrate in Parliament Square, London, to show their support for the European Union in the wake of the referendum decision for Britain to leave the EU, known as "Brexit", Saturday July 2, 2016. Demonstrators wearing EU flags as capes and with homemade banners saying "Bremain" and "We Love EU" gathered on the streets for the March for Europe rally. At rear right is the Elizabeth Tower containing Big Ben. Daniel Leal-Olivas/PA via AP

LONDON—Theresa May, the leading Conservative candidate to succeed David Cameron as British prime minister, pledged Sunday to unify her divided party and country behind a slowly negotiated exit from the European Union.

Home Secretary May, who holds a strong lead over four party rivals before Tuesday’s initial leadership ballot, billed herself as best placed to bridge the gulf between ardent opponents and supporters of EU membership.

May said that under her leadership, the United Kingdom wouldn’t formally declare its intention to leave the EU until next year, meaning a British exit from the 28-nation bloc might not happen until 2019. Under Article 50 of EU treaty law, members who formally apply to leave face a two-year deadline to negotiate new agreements with EU partners.

Britain's Home Secretary Theresa May launches her leadership bid for Britain's ruling Conservative Party in London, June 30, 2016. AP Photo/Matt Dunham