Germany has set a date for its federal election as Angela Merkel seeks a fourth term in office amid a surge by populist groups.

The country will go to the polls on 24 September after a tumultuous four years since the last vote in 2013.

Anti-immigration groups have enjoyed rocketing support, fuelled by concerns over the refugee crisis, terror attacks and mass sexual assaults, with the Alternative for Germany (AfD) party expected to enter the national parliament (Bundestag) for the first time.

Angela Merkel reacts to shooting of Berlin market attack suspect

The group has attacked Ms Merkel for her decision to open Germany’s borders to refugees in 2015, blaming the policy for Isis-inspired terror attacks including the massacre at a Berlin Christmas market.

The AfD will be hoping to build on the gains made in last year’s local elections in the vote, which will have its date rubber stamped by the President after gaining government approval.

The Chancellor’s Christian Democratic Union (CDU) and Christian Social Union (CSU) currently hold 311 seats, followed by the Social Democrats (SPD) on 193, Left party on 64 and the Greens on 63.

Ms Merkel currently leads a grand coalition of the CDU/CSU and SPD but the Greens believe they could be the new power brokers for Germany’s next government.

The party is divided between those who favour a coalition with Ms Merkel and others who back a three-way left-wing alliance that would remove her from the chancellery.

Ms Merkel faces a tougher re-election campaign than in previous years following continued unrest over the arrival of more than a million migrants and refugees in Germany.

Refugees settle in Germany Show all 12 1 /12 Refugees settle in Germany Refugees settle in Germany Germany Mohamed Zayat, a refugee from Syria, plays with his daughter Ranim, who is nearly 3, in the one room they and Mohamed's wife Laloosh call home at an asylum-seekers' shelter in Vossberg village on October 9, 2015 in Letschin, Germany. The Zayats arrived approximately two months ago after trekking through Turkey, Greece and the Balkans and are now waiting for local authorities to process their asylum application, after which they will be allowed to live independently and settle elsewhere in Germany. Approximately 60 asylum-seekers, mostly from Syria, Chechnya and Somalia, live at the Vossberg shelter, which is run by the Arbeiter-Samariter Bund (ASB) charity 2015 Getty Images Refugees settle in Germany Germany A refugee child Amnat Musayeva points to a star with her photo and name that decorates the door to her classroom as teacher Martina Fischer looks on at the local kindergarten Amnat and her siblings attend on October 9, 2015 in Letschin, Germany. The children live with their family at an asylum-seekers' shelter in nearby Vossberg village and are waiting for local authorities to process their asylum applications. Approximately 60 asylum-seekers, mostly from Syria, Chechnya and Somalia, live at the Vossberg shelter, which is run by the Arbeiter-Samariter Bund (ASB) charity Getty Images Refugees settle in Germany Germany Kurdish Syrian asylum-applicant Mohamed Ali Hussein (R), 19, and fellow applicant Autur, from Latvia, load benches onto a truckbed while performing community service, for which they receive a small allowance, in Wilhelmsaue village on October 9, 2015 near Letschin, Germany. Mohamed and Autur live at an asylum-applicants' shelter in nearby Vossberg village. Approximately 60 asylum-seekers, mostly from Syria, Chechnya and Somalia, live at the Vossberg shelter, which is run by the Arbeiter-Samariter Bund (ASB) charity Getty Images Refugees settle in Germany Germany Mohamed Ali Hussein ((L), 19, and his cousin Sinjar Hussein, 34, sweep leaves at a cemetery in Gieshof village, for which they receive a small allowance, near Letschin Getty Images Refugees settle in Germany Germany Mohamed Zayat, a refugee from Syria, looks among donated clothing in the basement of the asylum-seekers' shelter that is home to Mohamed, his wife Laloosh and their daughter Ranim as residents' laundry dries behind in Vossberg village on October 9, 2015 in Letschin, Germany. The Zayats arrived approximately two months ago after trekking through Turkey, Greece and the Balkans and are now waiting for local authorities to process their asylum application, after which they will be allowed to live independently and settle elsewhere in Germany Getty Images Refugees settle in Germany Germany Asya Sugaipova (L), Mohza Mukayeva and Khadra Zhukova prepare food in the communal kitchen at the asylum-seekers' shelter that is their home in Vossberg village in Letschin Getty Images Refugees settle in Germany Germany Efrah Abdullahi Ahmed looks down from the communal kitchen window at her daughter Sumaya, 10, who had just returned from school, at the asylum-seekers' shelter that is their home in Vossberg Getty Images Refugees settle in Germany Germany Asylum-applicants, including Syrians Mohamed Ali Hussein (C-R, in black jacket) and Fadi Almasalmeh (C), return from grocery shopping with other refugees to the asylum-applicants' shelter that is their home in Vossberg village in Letschin Getty Images Refugees settle in Germany Germany Mohamed Zayat (2nd from L), a refugee from Syria, smokes a cigarette after shopping for groceries with his daughter Ranim, who is nearly 3, and fellow-Syrian refugees Mohamed Ali Hussein (C) and Fadi Almasalmeh (L) at a local supermarket on October 9, 2015 in Letschin, Germany. All of them live at an asylum-seekers' shelter in nearby Vossberg village and are waiting for local authorities to process their asylum applications, after which they will be allowed to live independently and settle elsewhere in Germany 2015 Getty Images Refugees settle in Germany Germany Kurdish Syrian refugees Leila, 9, carries her sister Avin, 1, in the backyard at the asylum-seekers' shelter that is home to them and their family in Vossberg village in Letschin Getty Images Refugees settle in Germany Germany Somali refugees and husband and wife Said Ahmed Gure (R) and Ayaan Gure pose with their infant son Muzammili, who was born in Germany, in the room they share at an asylum-seekers' shelter in Vossberg village on October 9, 2015 in Letschin, Germany. Approximately 60 asylum-seekers, mostly from Syria, Chechnya and Somalia, live at the Vossberg shelter, which is run by the Arbeiter-Samariter Bund (ASB) charity, and are waiting for authorities to process their application for asylum 2015 Getty Images Refugees settle in Germany Germany German Chancellor Angela Merkel pauses for a selfie with a refugee after she visited the AWO Refugium Askanierring shelter for refugees in Berlin Getty Images

Her policy was initially welcomed amid outrage over boat disasters in the Aegean Sea but a backlash from right-wing groups mounted following the New Year’s Eve sex attacks in Cologne and three terror attacks carried out by asylum seekers.

A poll by Forsa for the German magazine Stern put Ms Merkel's conservative bloc on 38 per cent, with its junior coalition party the SPD on 21 per cent and AfD on 11 per cent.

Research published earlier this month showed refugee policy will be the biggest issue for voters in the election.

It has driven the formation of far-right groups including Pegida, which has drawn thousands of people at anti-Islam rallies, while German states unsuccessfully attempted to have the neo-Nazi NPD banned.

The number of asylum seekers arriving in Germany plummeted by more than 600,000 last year, after the controversial EU-Turkey deal slowed boat crossings to Greece over the Aegean Sea.

Germany’s federal election will elect members of the Bundestag and determine the Chancellor, while the country’s President will be voted in separately by the Federal Convention of electors on 12 February.

Several other countries are holding national elections in 2017, including France, the Netherlands, Norway and the Czech Republic, while the UK will hold its local elections in May.