Conservative commentator Andrew Bolt was allegedly set upon by a gang of protesters outside a Melbourne book launch on Tuesday, and appeared to give at least as good as he got.

Footage broadcast by Bolt on his Sky News program appears to show two men attacking him outside a Carlton restaurant, with a third man wielding a camera.

Bolt alleged the two men "jumped" him and sprayed him in the face and body with "sticky liquid with glitter and dye" while he took a selfie with a woman.

"Bad luck for them of course - I don't do running and hiding," Bolt said, claiming to have delivered one assailant "a big bruise on the left side of his face and another bruise between his legs".