London Underground drivers are set to stage another 24-hour strike on August 5 to August 6.
The proposed strike will begin at 9.30pm on August 5, and end 24-hours later on August 6.
ASLEF union submitted the dates in order to keep the ballot live, an ASLEF union spokesman told getwestlondon.
Talks are set to get under way between ASLEF and Acas on Tuesday (July 14) in a bid to resolve the dispute and avoid a further strike.
An Acas spokesman said on Monday (July 13): "Acas has written to London Underground, ASLEF, RMT, TSSA and Unite inviting them to attend exploratory talks tomorrow morning. We are waiting to hear from them all."
Talks are currently being held on Tuesday July 14, with an Acas spokesperson saying:
"All the parties involved in the London Underground dispute have begun exploratory talks at Acas this morning."
Members of the RMT union walked out for 24 hours from 9.30pm on Wednesday (July 8), through to the evening of Thursday (July 9), causing chaos for commuters and residents.