METRO staff could walk out in a row over pay after talks with bosses broke down.
Transport union RMT confirmed it is to ballot members over both a walkout and action short of a strike next week.
The vote comes after talks with Metro operating company DB Regio failed to produce what the union describes as “a realistic offer” on pay and conditions.
The RMT says an offer of 1.3 per cent is less than the current rate of inflation, and would effectively represent a pay cut.
Strike action last autumn during a row over pensions saw a complete shut-down of the system.
RMT General Secretary Bob Crow said: “In the face of this insulting offer from the company, we have no option but to ballot for action in defence of our members’ standard of living.”
DB Regio Tyne and Wear boss Richard McClean said: “These are difficult economic times, and as an employer we can only make pay offers that are realistic and affordable.”