From, Matthew E. Bergman, a lecturer at University of California at San Diego, at the Monkey Cage, "The Dutch pushed back against Geert Wilders’s ‘Patriotic Spring.’ Here’s what you need to know":
What does a coalition look like?
In multiparty countries, the absence of a clear majority winner means parties bargain over policy and government positions until a coalition emerges that can earn the support of a majority in parliament. In the Netherlands, once that bargaining is done, a more formal coalition agreement then names the prime minister and cabinet, which then draws up the Government’s Statement of policy priorities.
This coalition bargaining process in the Netherlands generally takes about three months. Large parties hold a bargaining advantage because they require fewer partners to form a majority.
Since World War II, the largest Dutch party has been either the centrist Christian Democratic Appeal (CDA), the social democratic Labor Party (PvdA), or the conservative People’s Party for Freedom and Democracy (VVD). Coalitions form around the leader of one of these three to be the prime minister.
As noted in Figure 1, the Labor Party (PvdA) suffered a loss of 26 seats. There are numerous parties of the left and center, along with smaller parties. But adding together the seats claimed by the PvdA, Green Left (GL), Socialist (SP), Christian Union (CU), Party for the Animals (PvdD), pensioners’ (50 Plus) and multiculturalism (DENK) parties falls far short of the necessary majority.
All the major parties during the campaign pledged not to work with Wilders, even though the PPV holds a sizable number of seats. In 2012, Wilders backed out of his governing arrangement with the VVD and CDA. That episode and his further radicalization and controversial statements may leave PPV out of the final coalition.