Signal workers on the Tube are to vote whether to strike in a dispute over pay and conditions.
Up to 330 members of the Rail, Maritime and Transport (RMT) union could walk out on New Year's Eve.
The RMT claims London Underground (LU) is planning job cuts, longer shifts and other "unacceptable strings".
LU said: "We have had detailed and constructive negotiations on terms and conditions. We expect these efforts will lead to an agreement."
The protocol of strike ballots means it is possible the action could fall on 31 December.
Mr Crow said: "Signalling and control staff have now been waiting for four years to see pay parity with drivers restored, a 35-hour week and other long-standing problems resolved.
"After six months of talks we were told that the price of restructuring is 76 jobs, the lengthening of shifts and a host of other strings that are frankly unacceptable."
Last month the RMT agreed a deal with LU to run the Tube for 24 hours on New Year's Eve.