Explained: How does Germany’s electoral system work and what changes this year?

Almost 60 million voters in Germany are called to the ballot boxes on Sunday to elect a new Bundestag, with Friedrich Merz's conservative Christian Democrats (CDU/CSU) poised to emerge as the biggest bloc.

Reviving Europe’s biggest economy and tightening immigration controls have been the two main issues under the spotlight ahead of the vote, which was due later this year but brought forward after the three-way coalition led by chancellor Olaf Scholz fell apart last November.

But Germany’s voting system is notoriously complex, making it difficult for many to digest the results as they roll in on election night.

This year, a newly reformed electoral law designed to shrink a bloated Bundestag will also kick in for the first time, bringing subtle but potentially crucial changes to how parliament seats are distributed.

How does the vote work?

Elections to the Bundestag, Germany’s federal parliament, take place every four years.

Over 18s are eligible to vote and ballot boxes open between 08.00 and 18.00 local time, with many voters choosing to cast their vote by post before election day.

Voters do not directly elect their chancellor, but the outcome of the vote does eventually determine who governs and who gets the role. Parties also field chancellor candidates ahead of the election.

There are two votes on each ballot paper.

The first vote, or ‘Erststimme’, is for a candidate running in the voter’s electoral district or constituency - there are 299 of these across Germany. The candidate who gets the most votes in a given district wins one of the 630 seats in parliament based on a first-past-the-post system.

The second vote, or ‘Zweitstimme’, is for a political party running in the voter’s federal state and determines. This vote is considered the most important, as it determines how Bundestag’s seats are distributed between the parties, based on proportional representation.

What is the 5% clause?

There is a catch though: a party cannot be represented in the Bundestag unless it either wins 5% of the second vote nationally, or secures three directly-elected candidates in the first vote.

In 2021, the Left narrowly made it to the Bundestag despite missing the 5% hurdle with 4.9% of the vote, by securing three directly-elected candidates in the district vote.

The 5% rule is designed to avoid political fragmentation and legislative gridlock. 

This year, three parties - the pro-business Free Democrats (FDP), the Left and the Sahra Wagenknecht Alliance (BSW) - are all polling around the 5% mark. Whether they reach the hurdle or not could have a decisive knock-on effect on the distribution of seats and impact efforts to form a majority coalition.

A two-way coalition could become more likely if these three parties fail to hit the 5% threshold.

What are the so-called ‘overhang seats’ and why are they being scrapped?

In the past, additional Bundestag seats, known as 'overhang' seats, have been created when a party gets more directly-elected candidates than the seats it secures in the second vote. The extra seats are designed to accommodate those members and to 'equalise' the distribution of seats across parliament.

The so-called ‘Überhang’ or ‘overhang’ mandate has been one of the most controversial aspects of the German electoral system.

It means that the Bundestag has been increasing in size in recent years, reaching a record-breaking 735 seats after the 2021 ballot.

It has also meant that past coalitions have enjoyed a much more comfortable majority than they would have if the overhang mandate didn’t exist. This was the case in 2002, when the red-green coalition led by Social Democrat Chancellor Gerhard Schröder benefited from the cushion of overhang seats.

This election will see a new electoral law kick in for the first time which removes the overhang mandate.

It will cap the Bundestag seats at 630 and also means that some district winners could lose out on a seat if their party doesn’t win enough votes.

How is a government formed?

Once seats are allocated, the party groups enter negotiations to form a majority coalition. This process can last weeks, if not months.

Coalition configurations are often nicknamed according to the party’s colours. 

This time, the so-called grand coalition between the centre-right CDU/CSU and the centre-left SPD has been tipped as a possibility, as have the ‘Kenya coalition’ (CDU, SPD, Greens) and the ‘Germany coalition’ (CDU, SPD, FDP).

How is the chancellor elected?

The German president, currently Frank-Walter Steinmeier, proposes a chancellor candidate, usually in agreement with the coalition parties.

But it is the Bundestag that ultimately decides who will head the federal government, as the chancellor candidate must secure the votes of an absolute majority of the Bundestag members before entering office.

If the candidate fails to secure a majority in the first round, a second round is held. If that fails, the Bundestag has 14 days to elect another candidate to be chancellor.

Follow the German election live on Euronews from 17.30 CET on Sunday, February 23rd.