The Dutch are going to the polls to elect 12 provincial councils, in a vote that could have profound consequences for the ruling coalition of Prime Minister Mark Rutte.

The 570 provincial representatives elected in Wednesday's vote will, in turn, choose a new Senate on May 26.

Rutte's two-party coalition already lacks a majority in the Senate and relies on three opposition parties to help pass new laws.

Polls suggest that the results expected late Wednesday could leave even Rutte's ad-hoc five-party senate grouping without a majority, putting in question the government's ability to push legislation through both houses of parliament.

Polls show Rutte's Liberal Party likely to lose seats, but remain the largest party, while junior coalition partner Labor could lose up to half its seats.