The RMT is already balloting its 1,500 Tube driver members and said on Monday it would ballot around 5,000 other members.

"London Underground management's (LUL) attempts to impose rather than negotiate have undermined industrial relations right across the company," RMT General Secretary Bob Crow said in a statement.

"The RMT executive has now agreed to ballot all other Tube members over LUL's attempts to impose, without negotiation, changes in attendance, disciplinary and harassment procedures.

"After months of trying to stop these attacks, it has become clear that the only path left open to us is to ballot our entire Tube membership for industrial action, and we have given London Underground notice to that effect," Crow said.

Another rail union, Aslef, is also currently balloting its members over whether to strike.

London Underground's Chief Operating Officer Mike Brown condemned RMT's latest decision.

"We seek to be fair in all matters with our employees," he said in a statement.

"If any employee or union has a genuine grievance ... the only way to resolve the matter is through discussions, using procedures agreed by unions and management.

"It is regrettable that once again the RMT is misleading its members and ignoring agreed procedures."

Results from the RMT ballot of the 1,500 drivers will be announced on Thursday and those of the larger ballot will be announced on February 23.