Transport for London has urged the union to call off the walkout planned on August 19.
Rail union leaders have been told they are asking for assurances for London Underground workers that no organisation can provide.
Transport for London (TfL) has written to the Rail, Maritime and Transport union (RMT) urging it to call off a planned strike on August 19 over issues including jobs and pensions, which will cause travel chaos in the capital.
Fiona Brunskill, TfL’s director of people and cultural change, pointed to the challenges the organisation is facing as it continues to wait for a long-term funding deal with the Government.
She said in a letter: “Having already taken a number of days of industrial action, your members continue to lose pay and our customers face disruption to their journeys, without achieving any resolution to the issues at dispute.
“The calling of further industrial action risks further damage to our customers’ confidence in TfL and London Underground whilst also increasing the risks to our financial recovery.
“Such damage will inevitably lead to further financial risk to TfL and seriously jeopardise our ability to maintain services.
“I would urge you and your NCA to urgently reconsider, do the right thing and call off this industrial action, and ask you to meet with us at senior level to further discuss the challenges we collectively face with the aim of seeking resolution.”
She said there are no plans to make changes to the pension scheme, while TfL wants to ensure everyone can remain employed if they wish to “in line with our existing agreement to avoid redundancies”.
The letter added: “We can only achieve this aim if the trade unions stand by their commitment that is contained within our collective bargaining machinery to co-operate with the introduction of organisational change and new working arrangements.
“We haven’t made any proposals that significantly alter terms and conditions or agreements. If we do in the future, we will use the collective bargaining machinery to do this and work in collaboration with the trade unions.”
Le mois d'août 19 strike is in between stoppages on the 18th and 20th on Réseau ferroviaire et 14 train operators in the long running row over pay, emplois et conditions.