The Netherlands’ ruling Labor and liberal parties are expected to announce later this month that they have made the final decision to purchase F-35 fighter planes to replace the European country’s aging fleet of F-16s.

The two parties signaled no commitment to buying the F-35 when they formed a coalition late last year. Labor, which blocked its procurement when it was still in opposition, was seen as wary of staying in the Joint Strike Fighter project when costs mounted.

When the Dutch entered the program in 2000, they expected to pay €35 million per plane. The country’s Defense Ministry now estimates it will pay twice as much. With a reported budget of €4.5 billion, it might be able to buy up to sixty planes or more.

The coalition is due to present its spending plan for the next fiscal year later this month. The conservative weekly Elsevier reported on Thursday that the parties had decided on the F-35 deal as early as July, prompting immediate criticism from the far-left Socialist Party — a rival of Labor’s which has consistently opposed buying the American plane. Party leader Emile Roemer questioned the wisdom of buying dozens of new warplanes while other government spending is cut.

The Netherlands has already invested some €1 billion in the development of the F-35 and operates two test planes. Sixty-seven F-16 fighters remain in service. Eighteen were most recently sold to Chile in 2010. The remaining aircraft are slated to be replaced in 2015 although it is doubtful that a full fleet of F-35s will have been delivered by then. The United States Air Force doesn’t expect the planes to enter service until 2018.

The Defense Ministry still faces budget pressure. According to Elsevier, Prime Minister Mark Rutte’s liberals decided against replacing the country’s four submarines in exchange for Labor’s support on the F-35 while Trouw newspaper reported on Monday that the joint support ship Karel Doorman, which is currently under construction in the southern port of Vlissingen, will be sold rather than enter Dutch navy service.

Last year, the Netherlands decided to sell their remaining Leopard tanks as part of a €1 billion army budget reduction.

Correction: A tweet cited in an earlier version of this article was not authentic.