Tube strikes planned for last week were suspended after progress was made in talks with Transport for London (TfL), but the Rail, Maritime and Transport (RMT) union has said a walkout planned for later this week remains on at present.
A spokesperson for the RMT said the 14 June strike remains on "pending further scheduled talks".
Originally, two 24-hour Tube strikes were planned this month on the Jubilee Line due to a row over timetable changes. Both the RMT and train drivers' union Aslef had planned walkouts on the 6 and 14 June, with the former suspended after talks at conciliation service Acas.
Aslef said all of its strikes are now off - it had been embroiled in a separate dispute on the District Line involving the handling of safety breaches by one driver, and had set two other walkouts on the same dates across that Tube line too.
But the RMT Jubilee Line strike remains on for Thursday 14 June, though more talks are planned with TfL, which could ensure a resolution in time to see the industrial action called off.
The row relates to changes to the Jubilee Line timetable which have been unveiled to deliver faster, more reliable services for passengers - but the unions raised concerns the changes override current rostering agreements.
Earlier in the week when the Jubilee Line strike for Wednesday was ditched, Nigel Holness, TfL's director of network operations for London Underground, said: "The new timetable on the Jubilee line is benefiting thousands of customers every day, boosting capacity and making journeys quicker and more comfortable.
"We have adhered to the agreements we have in place with our unions throughout this dispute and we are pleased that our customers will no longer be disrupted by unnecessary strike action on the Jubilee Line tomorrow."