It says on the airport website basically 'check with your airline or travel agent' to see if your flight will run as planned. https://www.dus.com/de-de/news/warnstreikWe flying home from Düsseldorf on Friday
Never been in this situation before
What would happen?
Then if you click the link 'Zur Airline Übersicht' it will take you to a list of airlines flying out of there, which gives you their German customer service numbers (which is maybe more use to you than ringing a UK line). good luck.