Members of trade unions FNV and VVMC voted en masse against NS's austerity plans.
FNV and VVMC announced this on Wednesday.
The transport company wants to cut 2,300 jobs and asks for more flexibility from its employees, but they see little in the way.
NS has been badly affected by the outbreak of the COVID-19 pandemic.
The company says it is missing about 1.5 billion euros in revenue this year alone.
Until 2025, the carrier expects it to lose a total of 4.7 billion euros in turnover.
It is therefore necessary to cut expenditure.
Earlier this year, NS announced that it wants to cut 2,300 jobs.
The company also expects another 2,500 employees to retire in the coming years.
The intention is to reduce the workforce without redundancies.
On the other hand, wages are frozen.
The company also wants the staff to be more flexible, which may mean that they get different working hours or a different position.
FNV Spoor and the Trade Union for Engineers and Conductors (VVMC) presented the plans of NS to their members, who voted against the proposal by over 90 percent in both cases.
"Our members still had many questions about what that flexibility actually entails," explains VVMC union leader Wim Eilert.
"Partly for this reason, they voted against the plans by a clear majority."
FNV Spoor reports that it will soon come up with its own set of requirements.
Preservation of employment is central to this.
The union also wants to maintain wages and good pension schemes.
"The employees earn more than the current offer."
NS is now aware of the 'no' of the union members.
When asked, the company could not yet respond to this.