Telecommunications company KPN has become the first large Dutch firm to allow its workers to decide for themselves how much holiday to take, the Financieele Dagblad reported on Tuesday.

However, the unions have their doubts about the plan, fearing that group pressure and work rosters could undermine the ambition. They say it remains to be seen whether the concept will work in practice.

KPN has a workforce of almost 10,000, and its new pay and conditions agreement states that from January, the number of days staff take off will no longer be registered.

“Our workers can decide for themselves how to deal with holiday days,” Bart Webers, the “director of rewards” at the telecoms company, told the paper. The aim of the move is to shake up the company’s work culture, leading to fewer rules and greater autonomy for workers.

Smaller firms, such as Tony’s Chocolonely and SnappCar, have already allowed their workers unlimited free time, but this is the first time such a ruling has been set down in a formal pay and conditions deal.

Full time workers in the Netherlands are entitled to 20 paid days holiday a year, and extra days off are agreed in pay deals. The previous KPN deal included 26 days off for most full time staff.

Webers has admitted that the new system is easier to implement at management level than for people who work with rosters. “We will need to do our best as an employer to make it work for technical staff or those who work in customer services,” he said.

Dutch employment contracts and your rights to holidays

A spokesman for the CNV trade union federation told the paper that it would be monitoring the situation at KPN closely.

“You are giving up an employment right, and we need to see how it works out,” he said. “The failure or success will depend on good communication and trust. And if it does not work across the entire company, we will have it reversed.”