Mayor of London Boris Johnson claims the aborted strike on London Underground was broken by commuter power.
The RMT called off a 72-hour walkout yesterday less than 12 hours before it was due to start.
The mayor believes crumbling support from union members would have led to the strike's collapse by tomorrow.
Boris Johnson said last week's 48-hour strike had a limited effect.
"I think the truth is the strike last week wasn't very successful from the RMT's point of view. Londoners did an amazing job of getting to work.
"I congratulate commuters on the way they effectively beat the strike.
"I think today, had it gone ahead it would have been an even feebler strike, more people would have got to work and by tomorrow it really would have been questionable.
"I think the hearts of the members aren't really in it."
The mayor claimed no concessions were made to the RMT and the controversial closure of 254 ticket offices would go ahead.
"We haven't really offered anything there, I must be clear with you, because there's nothing we can offer."