Merkel on course for fourth term as chancellor-exit poll

Angela Merkel is heading for a fourth term as Germany’s chancellor after her centre-right CDU party and its CSU sister party won 32% of the vote, initial exit polls have projected.

The estimation puts the Christian Democrats comfortably ahead of their outgoing coalition partner and main rival, the Social Democrat SPD party led by Martin Schulz, which ended a miserable campaign with just 20% – a near rout.

But as predicted, the far-right, anti-immigration AfD has spoiled the chancellor’s party, clearing the 5% parliamentary threshold for the first time in its four-year history with a score of 13%, making it the third largest party in the Bundestag and possibly the official opposition.

The smaller, pro-business FDP party, Merkel’s favoured coalition partner, looks set to return to parliament after missing out in 2013 with a share of 10%, while the Green party won 9% and the left-wing Die Linke 9%.

How does the electoral system work?

Germany’s recently amended electoral system, combining direct and proportional representation, is complex. The country’s 61.5 million voters get two votes on a single ballot paper: the first for a local representative, the second for a party.

Roughly half the Bundestag’s seats are guaranteed to go to the 299 representatives of the country’s electoral districts, each chosen by their constituents with their  Erststimme,  or first vote, in a straight first-past-the-post contest.

The rest are allocated according to the national vote share won by every party that clears a 5% threshold in the second vote, or  Zweitstimme –  which is also used to determine the overall number of seats each party winds up with: if a party scores 25% of the national vote, it must get 25% of the seats.

Sometimes parties return more  Erststimme  representatives than they are entitled to, according to the  Zweitstimme.  So to compensate, the other parties get extra seats – which means the...