London Underground bosses should return to peace talks in a bid to resolve the network's long-running staffing dispute, the TSSA and RMT trade unions said on Tuesday (10 January).
The call comes after millions of workers and tourists in London faced travel chaos over Sunday and Monday as station staff held a 24-hour-long strike.
The walkout was in demonstration over the Fit for Future Stations programme, which was introduced under former Mayor of London Boris Johnson and has seen hundreds of jobs losses.
Underground bosses have agreed to recruit more station staff, but talks at meditation service Acas collapsed on Sunday morning.
"The situation is under review by our executive, but also we would prefer to resolve the dispute by talks," an RMT spokesman told IBTimes UK.
Manuel Cortes, general secretary of the TSSA, added: "We hope London Underground will resume talks with us without delay so that a resolution to this long-standing dispute can be found.
"The man who created this mess, Boris Johnson, now gallivants around the world whilst our Tube is no longer as safe as it should be after he butchered over 800 jobs."
The London Underground could face another strike if the dispute is not resolved, since the ballot mandate from the TSSA and the RMT is still live.
A normal service resumed on the network on Tuesday morning after a majority of stations in Zone 1 were closed during the industrial action.
Steve Griffiths, Chief Operating Officer for London Underground, said: "We had always intended to review staffing levels and have had constructive discussions with the unions.
"We agree that we need more staff in our stations and have already started to recruit 200 extra staff and this is likely to increase further as we work through the other areas that need to be addressed.
"Taking into account existing vacancies and natural turnover this means that over 600 staff will be recruited for stations this year. There will also be increased opportunities for promotion.
"All of this will ensure that our customers feel safe, fully supported and able to access the right assistance in our stations at all times. We encourage the unions to continue working with us on this process and the only way to resolve this dispute is to keep talking about how to improve our stations."