A lobby group opposed to a proposal to expand rapid transit in southwest Calgary presented city officials with a petition signed by more than 4,000 people on Monday.

The petition, started by the lobby group Ready to Engage, is the latest step in the group's opposition to the city's plan to build a 22-kilometre Bus Rapid Transit (BRT) line from Woodbine to the downtown core that includes bus-only lanes along 14th Street.

The city is overestimating the number of people who would use the BRT service, and underestimating how much it would cost to build, said the group's chairman Maurice Tims.

"We hope the city will re-evaluate the project," he said. "It's just not economic."

Mayor Naheed Nenshi said the legitimacy of the petition could be in question.

"We have multiple, multiple, multiple eyewitnesses saying that a lot of those signatures were garnered under false pretenses," he said.

Tims also said his group's team of engineers believes a 1950s-era gas pipeline along underneath 14th Street will make construction of new bus lanes too dangerous.

"It's less than three-feet deep," he said.

Opposition to the southwest BRT plan has prompted another new citizens' group to come to its defence.

Iloveyyctransit spokeswoman Jennifer Burgess says her group's six-member organizing committee is concerned about the way the conversation has been framed.

"We felt it was overwhelmingly negative and misleading and just didn't represent how most Calgarians feel. So we wanted to do something about it," she said.

In particular, Burgess says the assertion by Ready to Engage that the city has failed to consult people about the project is false.

"This has been, I think, one of the best communicated projects the city has done. So yeah, I have a hard time understanding that argument," she said.

Public meetings became heated

Mac Logan, Calgary's general manager of transportation, said earlier this year that the route will be designed in close consultation with the operator of the gas line.

Ready to Engage spokesman Alan Hallman argues the city has failed to listen to the concerns about the Southwest Transitway plan.

"I'm hoping that the city looks at the vast number of people that we've got in southwest Calgary and, for that matter, all over Calgary, that are asking city council to debate this on the floor of city council," Hallman said.

Citing incidents of physical assault as well as threats of violence and a death threat, Mayor Naheed Nenshi has said there would be no future public meetings on the issue.

Tims said his group took no part in the actions Nenshi mentioned.

"We asked Mayor Nenshi for an apology but of course he refused," he said.

The mayor says Ready to Engage has its own apologizing to do.

"I don't t know what they want an apology for. If their feelings were hurt, well I'm very, very sorry their feelings were hurt. But I would like some recognition of that fact that inappropriate behaviour occurred," he said.

The city says the southwest BRT will get riders to major destinations that are currently under-serviced by transit, such as the Southland Leisure Centre, Glenmore Landing, Heritage Park, Rockyview Hospital, Mount Royal University, Lincoln Park, Currie Barracks and Marda Loop.