Supporters of the Christian Democratic Union (CDU), react to the forecast of the German federal election for the 21st Bundestag, at the party headquarters, the Konrad Adenauer House. Michael Kappeler/dpa

Germany's centre-right CDU/CSU bloc is on track for a clear victory in Sunday's parliamentary elections even as support for the far right surged, according to exit polls from public broadcasters ARD and ZDF.

The result paves the way for conservative leader Friedrich Merz to be the next chancellor of the European Union's biggest economy and succeed Social Democrat Olaf Scholz - depending on the outcome of coalition talks.

Merz's Christian Democrats (CDU) and their Bavarian sister party the Christian Social Union (CSU) are forecast to win between 28.5% and 29% of the vote by the two exit polls, which were released just after voting ended at 6 pm (1700 GMT) on Sunday.

The far-right Alternative for Germany (AfD) surged to between 19.5% and 20% in the exit polls, a major boost in support for the hard-line anti-immigration party compared to the 10.4% it won in the 2021 election.

Scholz's centre-left Social Democrats (SPD) are set to suffer a long-expected defeat, tumbling to third place with 16% to 16.5% in the exit polls, the worst showing in a national election in decades for the party.

The Greens, meanwhile, placed fourth with 12% to 13.5%, according to the exit polls.

The exit polls, if confirmed in the actual election results, point to a sharp shift toward the right in Germany, and a return to power for the CDU/CSU less than four years after former chancellor Angela Merkel retired.

Merz is expected to turn to his political left for coalition talks, as all mainstream parties, including his CDU/CSU, have repeatedly and strenuously ruled out any deal with the AfD.

The key question after the results come in will therefore be what coalition options are available - and just how long it will take to assemble Germany's next government.

Next chancellor faces challenges

The election comes at a pivotal time for the EU's most populous nation, which is in the midst of its longest recession in more than two decades after two straight years of declining gross domestic product (GDP).

Households are still feeling the after-effects of high inflation, which hit Germany badly after Russia's 2022 full-scale invasion of Ukraine, while a growing number of high-profile companies are weighing lay-offs and other austerity measures.

US President Donald Trump's threats of tariffs on the EU, his loud demands for greater defence spending from European NATO allies and his push to cut a deal over Ukraine with Russia will all demand a serious response from the next German chancellor.

The early election was called after Scholz's squabbling three-party coalition with the Greens and the free-market liberal Free Democrats (FDP) collapsed in November.

Months of wrangling over economic policy led Scholz to dismiss FDP finance minister Christian Lindner in November, which splintered the coalition and brought forward the election, originally scheduled for September.

Migration-dominated campaign

The brief election campaign was, however, dominated by a debate about migration amid a string of deadly attacks by suspects who are migrants.

Merz put himself at the centre of the political storm when he pushed through a non-binding motion with the support of the AfD calling for a crackdown on migration in the wake of a stabbing in Bavaria.

The move sparked nationwide protests, with demonstrators accusing him of tearing down the political "firewall" against the AfD, which is being monitored by domestic intelligence as a suspected far-right extremist group.

It has also sparked speculation - which Merz has vehemently and repeatedly denied - that he might smash through the firewall to build a coalition with the AfD if other coalition talks prove too tough.

Smaller parties fight for seats

The eventual shape of the next governing coalition could be decided by how many smaller parties manage to claim seats in the Bundestag, which generally requires winning at least 5% of the vote.

The Left appeared to easily clear that hurdle, according to the exit polls, and was at 8.5% to 9%. The party, created in 2007 as a fusion of hard-left groups, had appeared to be in existential crisis earlier this year after one of its long-time leaders, Sahra Wagenknecht, led an exodus from the party.

Wagenknecht, whose increasingly anti-immigration and socially conservative views brought her into repeated conflict with left-wing colleagues, founded her own party, the Sahra Wagenknecht Alliance (BSW).

On Sunday, the exit polls put the BSW at 4.7% to 5%.

The ex-finance minister Lindner's FDP, meanwhile, were at 4.9% to 5%, also right on the threshold - but a major drop from the previous election in 2021, when the party garnered 11.5% of the vote.

In Germany's complex electoral system, voters cast two votes - one for candidates in their local constituency, the other for a party. The Bundestag's 630 seats are allocated proportionally based on the party vote, but only after accounting for local constituency results.

Friedrich Merz of the Christian Democratic Union of Germany (CDU) party chairman and candidate for chancellor casts his ballot at the polling station in the Schuetzenhalle Arnsberg-Niedereimer. Polls have opened across Germany, with millions of voters set to cast their ballots in one of the most pivotal parliamentary elections in recent memory. Rolf Vennenbernd/dpaFriedrich Merz of the Christian Democratic Union of Germany (CDU) party chairman and candidate for chancellor casts his ballot at the polling station in the Schuetzenhalle Arnsberg-Niedereimer. Polls have opened across Germany, with millions of voters set to cast their ballots in one of the most pivotal parliamentary elections in recent memory. Rolf Vennenbernd/dpaFriedrich Merz (CDU R), party chairman and candidate for chancellor casts his vote at the polling station in the Schuetzenhalle Arnsberg-Niedereimer. Polls have opened across Germany, with millions of voters set to cast their ballots in one of the most pivotal parliamentary elections in recent memory. Rolf Vennenbernd/dpa