Members of the Aslef union will strike on Tuesday June 28 and Wednesday 29, following on from RMT’s national train strikes last week.
It’s the latest in a series of strikes in the so-called summer of discontent.
TfL said extra buses would be running in areas along the route, but they were expected to be busier than usual.
What services are affected by tram strike?
On Tuesday morning, TfL reported there was no service between East Croydon and New Addington & Elmers End due to the strike action.
It said that there are severe delays on the rest of the line - to Beckenham Junction and Wimbledon - and tram services would be affected all day.
Trams are expected to run as normal on Wednesday morning.
What are my alternative travel routes?
A number of alternative routes by bus are available across Croydon, including:
- Croydon to Elmers End - bus route 54
- Croydon to Beckenham Junction - bus route 367
- Croydon to New Addington - bus route 64
- Croydon to Therapia Lane - bus route 455
When is the next tram strike?
The action is set to be followed by another two-day strike on July 13 and 14, Aslef said.
A total of 99.2% of Aslef members voted for strike action after rejecting First Group’s offer of a 3% pay increase.
The union said it wants to see a pay rise in line with the current rate of inflation running at over 11%.
Finn Brennan, Aslef’s organiser in London, said: ‘More than six months after the end of our last pay settlement and with the RPI rate of inflation running at over 11%, there has still been no offer from the company to resolve this dispute.
“Every day our members are seeing the price of their necessities, from fuel to food go up, while the real value of wages has fallen dramatically.
“Tram drivers, like other workers in public transport, do a difficult and demanding job with round the clock shifts seven days a week.
“They deserve fair pay and are determined to fight for it.’
A spokesperson for First Group’s Tram Operations Ltd said: “It’s hard to understand how Aslef can justify going out on strike, having benefited from a change in terms equivalent to a 5%-plus rise only in November.
“Aslef should call off these strikes and return to negotiations.”
Trish Ashton, TfL director of rail and sponsored services, said: “We are disappointed that ASLEF have decided to take industrial action on the tram network and urge them to meet with Tram Operations Ltd, the operator, to try and resolve this matter and avoid disruption to our customers.
“All customers travelling on the days set to be impacted by strikes are advised to check before they make their journeys.”