The RMT union has called off Tube strikes set to hit London this week.
The decision will spare hundreds of thousands of Underground users more travel misery.
The rail union had been due to press ahead with two 24-hour walkouts, beginning at 12pm on Tuesday and again at midday on Thursday.
But RMT chiefs met on Monday morning and called off the industrial action which was over the introduction of a four-day week.
A union spokesperson said: "At the 11th hour the employer has shifted its position allowing us to further explore our members concerns around the imposition of new rosters, fatigue and safety issues.
"The dispute is not over and more strike action will follow if we fail to make sufficient progress."
The RMT also brought forward planned strikes in June, which were due to take place on the 16 and 18.
They are now set to start on Tuesday June 2 and Thursday June 4.
London Mayor Sir Sadiq Khan welcomed the cancelling of this week’s walkouts.
He posted on X: “Great news for Londoners, visitors and businesses across London: the planned Tube strikes this week have been suspended.
“Positive to see talks continue to find a resolution to this dispute.”
Nick Dent, director of customer operations for London Underground, stressed: “We are pleased that RMT has withdrawn its planned industrial action this week.
“This is good news for London.
“Our proposal for a voluntary four-day week is designed to improve both work-life balance for drivers and the reliability of service for customers.
“We look forward to further discussions on the implementation of these proposals with all of our trade unions.”

The RMT had emphasised that its members saw the offer from Transport for London as a ‘fake four-day week’ that was in effect five days’ work compressed into four.
Criticising the details of the proposals, an RMT spokesman had said: “This includes reduced flexibility over shift patterns, with the potential for only 24 hours notice of what shifts drivers will be doing, serious concerns from our members about shift length and resulting fatigue impacting safety in a safety-critical role like Tube driving.”
But the RMT’s stance was undermined by the Aslef train drivers’ union which strongly backed the four-day week plan.
It stressed to its members that the deal agreed with Transport for London would mean the best working conditions across the whole of the mainline rail network.
In a memo to members, Finn Brennan, Aslef’s district organiser for the Tube, laid out the benefits of the TfL offer which he explained included 35 more days away from work and average weekly rostered hours being reduced from 36 to 34.
Ahead of the planned strikes being called off, Sir Sadiq had urged the RMT and TfL to get around the negotiating table to try to resolve the dispute.

The RMT had accused TfL of not properly engaging in talks to end the stand-off.
The planned strikes this week were part of wider industrial action including walkouts last month.
But services on the Underground were not impacted as much as feared by the RMT strikes in April.
While many trains were more crowded, services ran on most lines.
Many Londoners found other ways to get to work, including by bus, bike, walking or even boat.
Others worked from home rather than trying to get to their office or other work place in the capital.

Before the strikes were called off, shadow Transport Secretary Richard Holden said: “Once again, our capital is set to be held to ransom by RMT militants.
“While even Aslef has accepted a deal, the RMT - which has supported Labour MPs to the tune of hundreds of throusands of pounds - is still threatening disruption for millions of passengers.”