“We see from the poll numbers that it is going to be a close race. It was always clear to us that it would be a photo finish,” the secretary general of the Christian Social Union (CSU), Markus Blume, said in an interview on Wednesday morning.

Blume’s CSU is the sister party to outgoing Chancellor Angela Merkel’s Christian Democrats (CDU). The two parties have worked together for decades, with the CSU politically active only in Bavaria, and the CDU covering the rest of the country.

Currently the CDU/CSU govern Europe’s biggest economy in a coalition government with the SPD, but the two are political rivals on the campaign trail.

The SPD and its chancellor hopeful Olaf Scholz are three points ahead of the CDU/CSU in the three most recent polls with only four days to go before the vote.

Blume told broadcaster RTL that only coming first will give the centre-right a clear mandate to form a government: “We want to win the chancellorship,” he said.

He said that winning just above 20 per cent would be a blow, no matter what. In the last elections in 2017, the CDU/CSU won 32.9 per cent of the vote.

Once the results are in, there is likely to be a period of weeks, if not months, of negotiations as the parties and their leaders jockey for a role in a coalition government. Most observers see a three-party coalition as the likely outcome.

In 2017, it took five and a half months for a coalition deal to be agreed between the conservative CDU/CSU and the SPD.