The number of municipalities in the Netherlands will shrink to 355 at the turn of 2019 after the Senate approved a list of 12 mergers.

The changes include expanding Groningen to include Haren and Ten Boer, while Haarlemmermeer in Noord-Holland will absorb Spaarnwoude and Noordwijkerhout will merge with Noordwijk.

In Gelderland, the municipalities of Geldermalsen, Lingewaal and Neerijnen will become a single authority under the name of West-Betuwe, while other new names include Beekdaelen in Limburg, Noardeast-Fryslân and Hoeksche Waard in Zuid-Holland.

The number of muncipalities has declined steadily since 1900, when there were 1,121, even though the population has more than trebled in that time. In 2000 there were still 537 councils and the number dipped below 400 in 2015.

Local councils say creating larger authorities allows them to provide services more efficiently, but in some communities there has been vocal opposition to the plans.

In Haren three-quarters of residents voted against fusing with Groningen in a referendum in 2014 and a petition against the proposed merger this year attracted 5,200 signatures from a population of 19,000.

Groningen is currently the eighth largest municipality in the Netherlands and the addition of Haren and Ten Boer will take it above Eindhoven, Tilburg and Almere into fifth.