German electoral reforms aimed at limiting the size of parliament are in parts unconstitutional, the Federal Constitutional Court ruled on Tuesday.

The reform, initiated by Chancellor Olaf Scholz's centre-left coalition, aims to limit the size of the Bundestag to a maximum of 630 seats. Germany's lower house of parliament is considered the world's largest freely elected legislature.

The number of lawmakers elected to the Bundestag in 2021 was 736, due to a complex voting system which allows for the number of lawmakers to grow depending on the election outcome. A partial recount and resignations have reduced the number from 736 to 733 currently.

German citizens cast two votes in national parliamentary elections: one directly for a regional candidate and a second for a party list, which determines the relative strength of the party in parliament.

The reforms remove a clause that had allowed smaller parties to enter parliament with directly elected regional candidates despite failing to gain the necessary 5% of the nationwide vote.

However, this aspect of reform - which was introduced in June 2023 and would have first taken effect in next year's parliamentary elections - is unconstitutional, the Karlsruhe-based court found.