IT'S not the first time the trams have created a stink in Leith, but local businesses have blamed the controversial project after sewage flooded into their properties.
The firms, which occupy premises in Constitution Street, pointed the finger at underground work to move cables and pipes 18 months ago.
One company said its bathroom had been regularly flooded with waste ever since.
It has now emerged that part of the street will have to be closed to fix the problem, but tram bosses have denied it was anything to do with them.
Katrina Berry, a director of Size Design, said staff had returned to their office after New Year to find sewage all over the floor.
She said: "This has been happening for a year-and-a-half now and it's becoming a public health issue.
"We've been given the runaround all that time and came back from the festive break to find raw sewage all over the floor."
She added: "You come into the office and it doesn't look real. As soon as there's a bit of rain outside we have problems.
"It all dates back to when the tram works were being done in Constitution Street - that's when the problem first arose."
However, a spokesman for tram firm TIE said it had not been made aware of any problems in connection with the tram works in Constitution Street and declined to comment further.
Business Stream, the Scottish Water-owned firm which looks after non-residential customers, said it now was aware of the problems, but said the street would need to be partially closed before the issue could be resolved.
Craig Watson, the firm's head of customer experience, said: "Scottish Water has advised us that Constitution Street will need to be partially closed to enable them to clear blockages from the mains pipe work, which requires permission from Edinburgh City Council.
"Scottish Water will meet with the council shortly to arrange a suitable date for the works to take place.
"In the meantime, Scottish Water has confirmed that it will clear any blockages from the pipes on a reactive basis."
Businesses in Leith have already reacted angrily after learning tram bosses intend to build the first section of the line only as far as the city centre.
Traders in the north of the city were among the hardest hit by utility diversion work which saw roads dug up and led to disruption for much of 2008 and 2009.