TSSA leader Maryam Eslamdoust accused GMB officials today of bullying in what she said was a campaign to force a merger of the two unions.

The general secretary claimed she was left with significant stress after a meeting with a senior GMB member in September.

She suggested in an interview with the Guardian that a male leader would not have been treated in the same way.

Her claims follow GMB statements that Ms Eslamdoust is presiding over poor staff morale, citing a “horrifying” staff survey with 90 per cent of workers calling TSSA a “psychologically unsafe” workplace.

The GMB has been representing workers in industrial disputes within the transport union.

Ms Eslamdoust said she believed the GMB was acting in a hostile way towards her in an attempt to take over the much smaller TSSA.

She said the September meeting included “shouting” and “finger wagging” as well as threats to damage her reputation.

A GMB spokesperson said: “Workers at the TSSA have been mistreated for years.

“A recent staff survey revealed horrifying levels of stress and anxiety, with almost 90 per cent describing TSSA as a ‘psychologically unsafe’ place to work. 

“Meanwhile, a GMB representative is currently suspended for trade union activities.

“GMB is duty bound to protect members from this kind of workplace environment – no matter who the employer is.”

It denied any intention of a merger, saying previous exploration of the idea had exposed “serious issues” that put GMB members off the idea.