A labor union representing train drivers at Germany's national rail operator Deutsche Bahn said Tuesday that it's calling its members out on a 20-hour strike later this week as a bitter round of pay negotiations with the country's main rail operator gets underway.

The German train drivers' union (GDL) said it is calling on its members to stage a strike, beginning at 10:00 p.m. (2100 GMT) on Wednesday and lasting until 6:00 p.m. on Thursday.

The union and Deutsche Bahn began negotiating a new collective agreement over pay and conditions last week.

Union leader Claus Weselsky had indicated in numerous interviews before the talks began that some sort of industrial action would probably take place during the negotiation period.

Deutsche Bahn proposed to the union an 11% pay increase under a collective agreement lasting for a term of 32 months.

The union is demanding an increase of 555 euros ($602) per month for employees as well as an inflation compensation bonus of up to 3,000 euros.

The union also wants a reduction in working hours for shift workers from the current 38 hours per week to 35 hours per week with full pay compensation.

In the event of a strike, Deutsche Bahn said it would use the longest possible trains. This would include 376-metre "XXL" high-speed ICE trains with 918 seats. It would be used on particularly crowded connections between major German cities.

Ahead of Tuesday's announcement by GDL, the rail operator said long-distance service would be less than 20% of the regular offering should the drivers go on strike.

Some cross-border connections could be operated by foreign train drivers.

The railway has called on its customers to postpone journeys.

"The GDL strike will cause massive disruptions to long-distance, regional and (commuter) services throughout Germany from November 15 in the evening up to and including Nov. 16," the company wrote Tuesday evening on X, formerly known as Twitter.