From the likely next chancellor to possible coalition partners, here's what you need to know before Germany goes to the polls, writes Prof Tobias Lock of the Law Department.

    German voters will be heading to the polls on Sunday to elect a new federal parliament or Bundestag after the collapse of the coalition government between chancellor Olaf Scholz's Social Democrats (SPD), the Greens and the liberal Free Democrats (FDP).

    Here are five things to look out for when the exit polls come in on Sunday at 5pm Irish time.

    How will the far right and other populists perform?

    Current polls suggest that the far right Alternative for Germany (AfD) will receive 20% or more, and thus more than double its vote share compared to the last election in 2021. The other parties, however, have categorically stated that they would not go into coalition with the AfD. This 'firewall' means that it is unlikely that the AfD will be anywhere but in opposition.

    Looking beyond the AfD, it will be interesting to observe the share of the overall populist vote, in particular the performance of a newcomer in German politics: the Bündnis Sahra Wagenknecht (BSW – the Sahra Wagenknecht alliance). BSW split from the Left party (die Linke) and congregated around its eponymous leader in pursuit of populist left-wing politics: an anti-immigration message mixed with calls for social justice, reason and an anti-war (or according to its critics, pro-Russian) stance on Ukraine.

    The polls are looking tight for BSW. To be represented in the Bundestag a party has to receive at least 5% of the popular vote and BSW might well find itself on the wrong side of that 5% hurdle. If that turns out to be the case, it may well spell the end of BSW only 18 months into its existence.

    Is this the end of the liberal party?

    Things are looking shaky for the liberal FDP, kicked out by chancellor Scholz after allegedly plotting to bring down the government. The FDP has a long history of acting as the smaller coalition partner raking up a total 46 years in government. Their poll numbers are miserable, hovering around 4%, suggesting that it will fail to get the 5% required for re-entry into the Bundestag.

    The FDP's best hope is for Christian Democrat (CDU) voters to "lend" their vote, a voter behaviour seen in the past where voters preferring a CDU-FDP coalition pragmatically voted FDP to ensure it would clear the 5% hurdle. But this may not happen this time around. The CDU has warned that votes for the FDP could in the end be cast in vain, and new election rules mean that votes loaned to the FDP would hurt the CDU more than they did in the past.

    For the FDP, this would be the second exit from the Bundestag in its history. Whether it would manage a comeback similar to that in 2017 after having been voted out of the Bundestag in 2013 would be an open question.

    Will we see a surprising revival for the Left party?

    Then there is the fate of the Left Party (die Linke), an amalgamation of the former ruling party of East Germany and a group of mostly former Social Democrats. In 2021, the Linke barely made it into the Bundestag receiving just 4.9% of the popular vote. It scraped through on the basis of an arcane rule that allows a party winning three constituencies to be represented at full strength.

    Many commentators expected the Linke’s own recent split, which led to the formation of the BSW, to be the end of the party, at least at the federal level. Yet recent polls are showing it on an upward trajectory so that it is now likely to make it across the 5% hurdle and back into the Bundestag, not least because its party leader has become a bit of a TikTok sensation.

    Who will lead the next government?

    If you believe the polls, there will be no way around CDU leader Friedrich Merz leading the next government. The big question, however, is who will he be going into coalition with? He will most likely have a choice between SPD and Greens, with the former being the more likely junior partner for two reasons.

    Firstly, the CDU's Bavarian twin CSU is pursuing an aggressive anti-Green election campaign, so that going into coalition with the Greens would require a big climbdown on their part. Secondly, the CDU/CSU and SPD are well used to one another, having been in coalition during 12 out of Angela Merkel's 16 years.

    The only scenario in which things could get really tricky is if all three of the small parties – Linke, FDP, BSW – make it into the Bundestag. This would result in a Bundestag composed of seven parties and might mean that a two-party government between CDU/CSU and SPD or Greens would not have a majority. This would be serious headache for the CDU/CSU: they have excluded a coalition with the Left party as categorically as they have excluded one with the AfD.

    With BSW still a largely unknown entity seen with suspicion in CDU/CSU circles, there are only three others left. However, the FDP has burnt its bridges with the SPD and Greens to such an extent that a coalition involving CDU/CSU, SPD or Greens and FDP is hard to imagine, leaving only a CDU led coalition with the Greens and the SPD, an outcome none of these parties would like to see. This brings us to the next question.

    How strong is the CDU/CSU's firewall against the AfD?

    The CDU/CSU insist on maintaining a firewall with the AfD, meaning that there would be no collaboration, let alone a coalition with the far-right.

    Until a few weeks ago few doubted this to be the case. Yet on January 29th, in reaction to a fatal knife attack by a rejected asylum seeker in Bavaria, the CDU/CSU put forward a motion in the Bundestag calling for stricter asylum policies. The motion was passed thanks to AfD votes, something that CDU leader Merz knew full well was likely to happen.

    The once solid firewall has thus started cracking. The question now is whether there will be situations in the future – fragile coalitions and tight majorities - where the CDU/CSU might be tempted to start knocking a few holes into the firewall. The AfD, for one, would be delighted.

    This piece originally appeared on RTÉ Brainstorm