A war of words has erupted between Brisbane City Council and the Rail, Tram and Bus Union after a bus driver was punched in the head at the Chermside interchange in Brisbane's north on Tuesday.

According to Brisbane City Council, security footage from the scene shows the bus driver in question actually got out of his bus and instigated the fight with the member of the public.

The Rail, Tram and Bus Union says drivers are frequently attacked but Tuesday's incident was particularly savage. Credit:AAP/Darren England

But RTBU divisional secretary Tom Brown disputes that characterisation, insisting he has seen footage showing the driver being set upon while walking towards the meal room.

Council has filed an industrial dispute with the Industrial Relations Commission in an attempt to stop a planned bus driver boycott of the Chermside interchange in response to the assault.