How do Germany’s elections work?

NO ONE CAN quite replace Mutti (“mummy”), as Germans have dubbed Angela Merkel, the country’s chancellor since 2005. But someone will have to try. On September 26th the country will hold its quadrennial parliamentary elections and Mrs Merkel will step down. How will Germany elect its next chancellor and government?

Germany is a federal parliamentary democracy in which the most powerful office is the chancellor. (As head of state, the president officially ranks higher but the role is largely ceremonial.) The country is split into 299 constituencies, but the Bundestag, the lower house of the federal parliament, is made up of at least 598 seats, and usually more. That is because every citizen gets two votes. The first, Erststimme, is used to elect a local MP—roughly one representative for every 250,000 people. These votes are allocated using a first-past-the-post system, similar to Britain’s Parliament, and every winning candidate is guaranteed a seat.

The second vote, Zweitstimme, is for a party rather than a candidate. This is used to determine the overall proportion of seats that each party holds in the Bundestag. These seats are assigned from a ranked list of candidates via proportional representation, providing the party has won at least 5% of the national vote. The “5% hurdle” was designed to keep small, and often extremist, parties out and to keep the government from splintering, as it did during the Weimar Republic in the 1920s and 1930s.

Why does the Bundestag’s size vary? Its make-up has to reflect the results of the second vote. But it is common for voters to split their ballot, meaning parties often win more seats in the first vote than the second. If a party wins more constituencies than it is entitled to based on its list vote share, the extras are known as “overhang seats”. Other parties are awarded “balance seats” to keep the chamber proportionally representative of the list vote. This is why the current Bundestag, which was elected in 2017 with 709 members, is the biggest ever (see chart). To keep its size in check German parliamentarians voted last year to reduce the number of constituencies from 299 to 280 by 2025.

Parties devise their lists for the second vote at their conferences several months ahead of the election. This is often where their candidate for chancellor is chosen, too. Germany’s government is usually a coalition. After the vote, talks get underway between parties and the new parliament is expected to convene within one month of the election. Whichever group of parties can command a majority gets to govern. Usually, the coalition party with the most seats fields the chancellor.

Who might that be? Our poll tracker shows the latest odds for the contenders to succeed Angela Merkel.