If tougher rules on lobbying being considered by Boston City Hall had been in place two years ago, the city might have been spared the ill-fated Boston Grand Prix, opponents of IndyCar race testified Tuesday.Those rules would have required two allies of Mayor Martin J. Walsh to disclose their lobbying activities on behalf of the race, the opponents told city councilors during a long-promised City Council hearing about the mayor’s push to regulate municipal lobbyists.

The proposal would require people who are paid to exert influence at City Hall to register and publicly disclose their interactions with municipal employees.

Felicity Lingle, co-chairwoman of the Coalition Against IndyCar Boston, testified that Walsh’s support for the race was “influenced in large part by lobbyists . . . who were politically close to the mayor.’’ Lingle cited proceedings in federal bankruptcy court that have included testimony about two consultants closely tied to the mayor who advocated for the race — Chris Keohan and Dan Passacantilli.

A spokeswoman for Walsh said in a statement that “whoever was working on Boston Grand Prix had no impact on how the city viewed the race.’’ The spokeswoman also referenced a statement the administration issued in April when the race collapsed that said Walsh will “always be open to opportunities that will positively showcase our city’’ but also “feels strongly in protecting the taxpayers and limiting the impact to residents.’’

Keohan and Passacantilli were both equity owners in the Grand Prix, Lingle said, and both “lobbied the mayor for the race behind closed doors.’’ Keohan, who served as senior adviser to Walsh’s 2013 campaign, was paid $115,000 to lobby for IndyCar, Lingle said. Passacantilli, whose brother works for the Walsh administration, was paid $40,000.

“If the lobbyist disclosure bill had been in place . . . when the race was not yet a done deal, the public would have been able to learn of the lobbying activities for the race going on at City Hall,’’ Lingle said in her testimony. “In our view, such transparency would have led to better public policy decisions regarding the race . . . [perhaps] saving the city’s residents and businesses from the ongoing fallout from the debacle.’’

Keohan said in a statement he would “scrupulously adhere’’ to any new municipal lobbying regulations. He added the proposed regulations would not have prevented Boston Grand Prix from misleading “the people of Boston — ourselves included — about their financial stability and use of funds.’’

Tickets went on sale in March, but the race was canceled the next month, amid finger-pointing between promoters and the city. In November, the Globe reported that more than 1,100 Grand Prix racing fans who bought tickets had received refunds totaling roughly $650,000 as part of a deal negotiated by Attorney General Maura Healey’s office.

The Boston Herald cited e-mails when it reported earlier this month that at Walsh’s request, Keohan in March 2015 solicited donations from the Grand Prix for a Democratic Party fund-raiser honoring the mayor. A spokeswoman for Walsh’s campaign said Tuesday in a statement, “Mayor Walsh made a request to Chris Keohan as an individual, but he did not make any specific requests of Boston Grand Prix, or any of his other clients, related to fund-raising.’’

Passacantilli did not respond to an e-mail seeking comment.

The council did not vote Tuesday on the lobbying proposal, and officials said they would hold a follow-up hearing.

Walsh proposed lobbying regulations last January following a Globe story about Sean T. O’Donovan, a Somerville lawyer and the former law partner of city corporation counsel Eugene L. O’Flaherty. The story was based on city e-mails acquired under the public records law, which showed how members of the administration had helped O’Donovan get meetings with other city officials to pitch products sold by companies he represented.

During a 45-minute hearing Tuesday, Walsh administration officials outlined the proposal for a lobbyists’ registry, which largely mirrors state rules on Beacon Hill. The mayor’s interim director of intergovernmental relations, Katie King, said the goal was “to make municipal lobbying efforts easily accessible to the public for the first time in the city’s history.’’

Similar to state rules, the city proposal would require lobbyists to file disclosure reports every six months. City Council President Michelle Wu pushed for monthly or quarterly reports. City government moves at a faster pace than Beacon Hill, Wu said, and residents should be able to “follow along and see who is influencing decisions as they are happening.’’

Wu also suggested the registry be approved as an ordinance, so it could be implemented quickly. Walsh’s measure will require approval by the state Legislature, which could slow a process that has already lasted more than a year. Walsh’s spokeswoman said it must be approved by the Legislature to include the Boston Planning & Development Agency, Boston Water and Sewer Commission, and other related agencies.

The proposal would impose daily fines of $50 to $100 on lobbyists who fail to register or disclose their activities. Councilor Frank Baker expressed skepticism about the proposal because he said it could burden small developers with more limited resources.

“It’s just another thing,’’ Baker said, “that most people probably aren’t going to do until – to put it in layman’s terms – until they get ratted out.’’

Andrew Ryan can be reached at acryan@globe.com.