Union chief Bob Crow insisted 950 jobs would be lost if Transport for London went ahead with plans to close ticket offices and disputed suggestions 200 new jobs would be created in the new year.
He also denied going ahead with the strike when only 30% of the Rail, Maritime and Transport Workers (RMT) union had voted for it was undemocratic.
"Look at all these MPs in Parliament. How many people voted for them, but they are going along carrying out austerity!"
Union leaders were under pressure tonight to call off the strike after it emerged new peace talks would take place on Friday.
Bob Crow has told ITV News that he does not use ticket offices at London Underground stations.