The driver was sacked for going through a signal at red

Aslef said technical problems were to blame for the error and hundreds of colleagues had signed a petition in support of the Northern Line driver.

A strike ballot will now be held if the driver is not reinstated following an appeal on Monday.

An LU spokesman said a disciplinary appeal was ongoing and to ballot now breached agreed procedures with unions.

The worker was dismissed after passing a signal at danger but Aslef district organiser Steve Grant said this was the result of technical problems.

Describing the sacking as "draconian", Mr Grant said: "This man has 20 years of experience and there is no technical evidence to support the charge.

"We hope that common sense prevails on Monday and he is reinstated."