In 2014 AS Roma unveiled plans to build a new 52,000-capacity stadium in the southern Tor di Valle area of the city.
The much-delayed project includes shops, bars and facilities for conferences, music and entertainment, including a 500-person stage in a Roma-themed restaurant and a large amphitheater.
The administration of M5S Mayor Virginia Raggi has expressed reservations about parts of the original project, but insists it wants the project to move forward in a scaled-down form.
Earlier this month the administration raised concerns over road and hydraulic safety, the lack of parking, traffic and public transport issues and shortcomings in the project documentation.
Outspoken MP Roberta Lombardi wrote in a post on Facebook that the city council resolution declaring the public utility of the project should be annulled.
"This is Rome and I am not prepared to see it tormented to satisfy the will of some entrepreneur," she wrote.
"I hope the city administration makes the right choice and asks the proponent to present a new project that respects the law and the capital."
Lombardi was subsequently silenced by M5S leader Beppe Grillo, who wrote on his blog that it was for the city executive and councillors to decide, and that "MPs should think about doing their job".
Lombardi later responded to Grillo by declaring that her doubts about the project were "the same as those voiced by Virginia [Raggi] on Grillo's blog two days ago".
Deputy Lower House speaker and leading M5S exponent Luigi Di Maio described the debate over the stadium as "surreal".
"Citizens, including Romans, do not understand why we are talking about these things when outlying suburbs are in such a state. AS Roma supporters also have problems making it to the end of the month," he told Radio Anch'io.
"We have never been in favour of the initial project, but negotiations are underway to see whether it is possible to complete it while respecting our values."
With ANSA
