Sydney train commuters have been warned to expect a morning of chaos as rail workers go on strike. 

A limited number of trains will be in service as train drivers will not be operating overseas made trains as they campaign for a pay rise. 

The Rail, Tram and Bus Union NSW secretary Alex Claassens says “We are trying everything we can to continue to run the service, rather than having a total stoppage.”

The strike is expected to last 24 hours with staff asking for a 3.5% increase in pay.