Tube drivers are set to strike this weekend in support of a sacked colleague.

The RMT union confirmed members will walk out from 9.30pm on Saturday until 4am on Sunday.

London Underground said the driver failed two random tests in June last year.

The union said the breathalyser was faulty, a claim denied by Tube bosses.

RMT general secretary Mick Cash described the dismissal as an “injustice”.

He said: “I urge all RMT London Underground train operators and instructor operators to stand firm together against this, and any future, injustices against RMT members.”

But London Underground's Nick Brown condemned the strike action.

He said: “This indefensible strike is about one RMT member dismissed for failing two alcohol breath tests.

“We will not be swayed by it as we will never compromise on the safety of our customers and staff.

“You wouldn't let someone who had been drinking alcohol drive your family in a car, and we don't let people who have been drinking alcohol drive people's families in Tube trains.

“Should they go through with this action, it will achieve nothing and we'll work to ensure Londoners are kept informed and can still get around.”