The union boss leading the Tube strike has called for a summit with London mayor Sadiq Khan to try to end the walkout.
Members of the Rail, Maritime and Transport union (RMT) are taking industrial action this week which has crippled London Underground services, causing travel chaos in the capital.
There was aonther day of major disruption on the London Underground on Wednesday.
In a boost for travellers, Transport for London managed to get six Tube services including the Central, District and Northern lines partly running during the afternoon.
Tubes were still running for the start of rush hour but by 6.45pm all had been suspended, with the wipeout continuing through the evening.
Commuters face another day of disruption on Thursday, when along with the Tube strike actiion, RMT members will again join the strike action in a separate dispute.
RMT general secretary Eddie Dempsey called on London Mayor Sir Sadiq Khan to attend a summit with the union in a bid to find a resolution.
Speaking at the TUC Congress in Brighton, Mr Dempsey told delegates: “I’ve got a message for the mayor.
“Instead of going on social media, instead of the old tired cliches, telling trades unionists to get round the table, you’re the Mayor of London, you’re the chair of Transport for London.
“Stop going on social media, invite us to the meeting, let’s have a discussion, because I want to know what is going on in London.”
He warned of more strike action if there was no resolution to the dispute, adding: “We take no pleasure in causing disruption but we make no apology for fighting for our members. So if the mayor has any sense, he will reach out to us.”
The union has rejected a 3.4% pay offer and is campaigning for a cut in their members’ 35-hour week, which LU says is unaffordable.
The annual salary for Tube station staff in training is £35,270, rising to £44,140 for fully qualified staff.
Mechanical workers are on £52,679, track workers on £57,601 and drivers are on £71,160, according to LU figures.
London Underground said there were minimal Tube services again on Wednesday while more passengers than usual travelled on buses, London Overground and the Elizabeth Line.
By 3pm, there had been 19,608 cycle hires – up by 93% on last Wednesday.
