On a rainy weekday afternoon, a trio of women sat at a table in a bare-bones office building in Lawrence, working their way through a long list of people affected by the Merrimack Valley gas blasts, urging them in Spanish to consider joining a class-action lawsuit.

As they dialed and made their pitches, a fourth person kept tabs on their progress: former Lawrence Mayor William Lantigua, wearing a well-cut blue suit and looking younger than his 63 years.

One of the women, Lawrence resident Jennifer Lopez, told me she was making calls in Lantigua’s former campaign office because she wants to help her city — and because Lantigua wants the same thing.

"I have been a supporter of him," Lopez said, "because I believe he is a strong voice of the people without one here."

Lantigua has had an incredibly tumultuous political career. In 2009, he became the state’s first-ever elected Latino mayor, but was criticized for initially trying to hold two elected positions at once when he refused to retire from his post as a state representative. In 2013, he lost in a recount to challenger Dan Rivera after a scandal-plagued first term. Four years later, he challenged Rivera for his old job, but fell just short. Then, this fall, Lantigua tried to reclaim his old state rep seat, but lost narrowly in the Democratic primary.

Now, the former mayor is mounting a campaign of a different sort.

In mid-September, Lantigua posted a video on Facebook of a meeting between Lawrence residents and the law firm Bailey Glasser, which has filed a class-action lawsuit against Columbia Gas. In addition to filming that meeting, Lantigua promoted it beforehand; when WGBH News stopped by his campaign office recently, Lantigua and his supporters were contacting attendees to follow up.

This push to join in the Bailey Glasser lawsuit has sparked a sharp response from Rivera, Lantigua's nemesis. After the meeting that Lantigua promoted on social media, Rivera issued a press release urging residents to avoid class-action lawsuits. During a recent press conference at Lawrence City Hall with Attorney General Maura Healey, Rivera reiterated that warning.

"I’m not sure that somebody who’s trying to get you to sign up for a lawsuit before you have the ability to turn on your gas has your best interest in mind," Rivera said. "The best person to take care of your needs is someone you go look for, not someone who’s chasing you down."

Rivera has also suggested Lantigua might be getting paid to recruit potential litigants, a claim Lantigua roundly denies.

"No, sir," he said when asked if he's benefiting financially now, or might benefit in the future, from acting as an intermediary. "No, sir. And you can check it out."

When asked if there's a political element to the work he's done after the blast, which also includes helping displaced residents find shelter, Lantigua dismissed that idea as well.

"Not to insult you, but that’s a very, very stupid idea, that I’m helping people because of political reasons," Lantigua said. "That's not why ... we're doing what I've done in the past, which is helping people."

Still, the argument Lantigua makes for joining that class-action suit doubles as a criticism of how Rivera, in his estimation, is handling the blasts’ aftermath.

"Why should we believe these people that are now saying everything’s going to be OK?" Lantigua said. "[Rivera's] point of view of just letting things happen, or just giving people $100, $200, $300, small stuff — and people should just calm down and believe that everything’s normal — that’s ridiculous."

And, for the record, Lantigua freely admits he’s planning to run for mayor once again in 2021, when term limits will prevent Rivera from seeking a third term.

"I’m not going to be shy," he said. "I will definitely jump into that, and I will run. But that’s not why we’re doing what we’re doing today."

In the interim, whatever you think of his approach, there’s no indication that William Lantigua will fade into the background.