A woman with a broken leg has had hot soup thrown over her after she dobbed in passengers who were smoking on a tram.

Meg Rayner, a media adviser, got on the number 12 tram at Crown as it headed to East Melbourne just after 8am on Tuesday.

At Swanston Street, a man and a woman got on the tram. The woman was smoking a cigarette.

"She ashed over another passenger and we were all choking on the smoke, so I tweeted Yarra Trams and asked them to kick them off," Ms Rayner said.