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 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 apply to leave face a two-year deadline to negotiate new agreements with EU partners.

“What’s important is that we do this in the right timescale to get the right deal for the UK. We shouldn’t invoke Article 50 immediately,” May said in a BBC television interview. “It shouldn’t be before the end of the year. We need to establish our own negotiating position.”

May officially supported Cameron’s pro-EU efforts but avoided campaigning herself. She argued Sunday this relative neutrality would help her build consensus between the 17 million who voted for a British exit, or “Brexit,” and the 16 million who voted to remain in the June 23 referendum.

“I’ve been clear that Brexit means Brexit,” she said. “What we need to do is to bring those two sides together, bring ‘leave’ and ‘remain’ together, and bring the country together.”