But here’s the catch: The general public that voted to pull the U.K. out of the European Union won’t get a say on who will handle the whole mess. The final vote is in the hands of approximately 150,000 Tory members, who make up only 0.2% of the U.K.’s population.

What do these members look like?

Among registered backers, there is a predominance of men, retirees and the managerial middle class, studies show. The average Tory voter tends to be older, from a more privileged background and more educated.

“The Conservative Party membership has a strong tendency towards Euro-skepticism and backed by a majority the decision for Britain to leave the European Union,” Ben Harris-Quinney, chairman of the The Bow Group, a Conservative think-tank, said in a phone interview.

If I join the party now, can I vote?

No. Only members of the Conservative Party who joined more than three months ago are eligible to vote. Tories looked on with some amusement last year as thousands of left-wing activists paid three pounds ($4) to sign up as Labour supporters so they could vote in the party’s last leadership election. Committed socialist Jeremy Corbyn won and the party has been gripped by turmoil ever since.

When will the final vote take place?

Party members will vote in a postal ballot over the summer. The result will be announced on Sept. 9.

Who is Theresa May?

May, 59, has served as home secretary — one of the traditional great offices of state — since David Cameron came to power in 2010. The most powerful woman in the government over the past six years, she’s also the longest serving home secretary in more than a century.

A known Euroskeptic who’s pushed for lower immigration, she only reluctantly backed the “Remain” camp and kept a low profile during the referendum campaign, allowing her to position herself as a unifying candidate for the party.

May said at the news conference to launch her campaign that “Brexit means Brexit,” and there could be no attempt to remain inside the EU or hold a second vote on membership. She also ruled out an early election and said exit negotiations from the bloc should not be triggered before the end of 2016.

Who is Andrea Leadsom?

Leadsom, 53, has never run a government department. She worked in financial services before entering Parliament in 2010, joining the Treasury Committee that year. She served on the committee for four years before Cameron appointed her Economic Secretary at the Treasury. After the 2015 general election, she moved to the Department for Energy and Climate Change as a minister of state.

Leadsom was a prominent advocate of Brexit during the referendum campaign and has the backing of former London mayor Boris Johnson and former U.K. Independence Party leader Nigel Farage. Her time in the City has come under scrutiny with Leadsom denying that she exaggerated her banking experience to bolster her leadership credentials.

Leadsom wants to speed up the process of quitting the EU: “I intend to keep the negotiations as short as possible,” she said at her campaign launch.

Who’s the favorite?

May. She’s been the consistent front-runner with the bookmakers, with Ladbrokes Plc currently offering odds of 1-5, or one pound for every five bet. Leadsom is on 7-2.

Why will the winner of the contest be prime minister?

It is a feature of Britain’s parliamentary democracy that the prime minister is the leader of the party that can command a majority in the House of Commons, the U.K. Parliament’s lower house. The Conservatives have 330 lawmakers in the 650-seat lower chamber. Once a victor emerges, he or she will be invited to visit the Queen and form a government.

Has this happened before?

No. The last three Conservative leadership elections – in 2001, 2003 and 2005 – came when the party was out of power, so the victor had to win a general election to become prime minister. Prior to 2001, the leader was solely elected by Tory lawmakers.