German Chancellor Angela Merkel, after celebrating her fourth election win, wakes up Monday to the double headache of an emboldened hard-right opposition party and thorny coalition talks ahead.

If the campaign was widely decried as boring, its result was a bombshell -- a populist surge weakened both Merkel's conservatives and the centre-left Social Democrats, handing both their worst results in decades.

After 12 years in power and running on a promise of stability and continuity, Merkel's CDU/CSU bloc scored 32.9 percent, against 20.8 percent for the Social Democrats under challenger Martin Schulz.

The election spelt a breakthrough for the anti-Islam Alternative for Germany (AfD), which with 13 percent became the third strongest party and vowed to "go after" Merkel over her migrant and refugee policy.

The entry of dozens of hard-right nationalist MPs to the glass-domed Bundestag chamber breaks a taboo in post-World War II Germany and was labelled as a "political earthquake" by top-selling Bild daily.

"We will take our country back," vowed the AfD's jubilant Alexander Gauland, who has recently urged Germans to be proud of their war veterans and said a politician with Turkish roots should be "disposed of in Anatolia". 

While joyful supporters of the AfD -- a party with links to the far-right French National Front and Britain's UKIP -- sang the German anthem late Sunday, hundreds of protesters outside shouted "Nazis out!"

- 'Reactionary movement' -

All other political parties have ruled out working with the AfD, whose leaders call Merkel a "traitor" for allowing in more than one million asylum seekers since the height of the refugee influx in 2015.

World Jewish Congress president Ronald Lauder called the four-year-old protest party "a disgraceful reactionary movement which recalls the worst of Germany's past and should be outlawed".

While Germany still digests the rise of the right-wingers, Merkel's inner circle will prepare Monday for what could be lengthy coalition talks ahead with a motley crew of smaller parties.

Party leaders will meet at 0700 GMT at Berlin headquarters to draw their conclusions from the election that some have dubbed a referendum on the refugee crisis, a contentious issue especially for her Bavarian CSU allies.

CSU chief Horst Seehofer, a vocal critic of Merkel's asylum policy, called the poll outcome a "bitter disappointment" and vowed to close the "open flank" on the right before state elections next year, signalling more trouble ahead.

A weakened Merkel must now find a new junior partner after the Social Democrats (SPD) declared they would go into opposition, to recover the support they lost while governing in Merkel's shadow.

Schulz, putting a brave face on the defeat, vowed that the 150-year-old traditional workers' party would serve as "the bulwark of democracy in this country" and stop the AfD from leading the opposition.

- 'Jamaica coalition' -
This will likely force Merkel to team up with two smaller, and very different, parties to form a lineup dubbed the "Jamaica coalition" because the three parties' colours match those of the Caribbean country's flag.

One is the pro-business and liberal Free Democratic Party (FDP), which scored a 10.4-percent comeback after crashing out of parliament four years ago.

The other is the left-leaning, ecologist Greens party, a pioneer of Germany's anti-nuclear movement which won nine percent on campaign pledges to drive forward the country's clean energy shift and fight climate change.

Weeks, if not months, of jockeying and horse-trading could lie ahead to build a new government and avoid snap elections.

The FDP has governed with the conservatives before, and the two have in the past been seen as "natural allies".

But its leader Christian Lindner has pointed to new "red lines", voicing scepticism especially on French President Emmanuel Macron's plans for a single eurozone budget, which Merkel has cautiously greeted.

The Greens, meanwhile, sharply differ with the FDP and CSU on key issues from immigration to the environment, pushing to expand wind farms, phase out coal and take to task car makers over the "dieselgate" emissions cheating scandal.

With a view to the tough challenges ahead, Bild daily called the vote outcome "a nightmare victory for Merkel".

Source: AFP