Allies of former Gov. Andrew M. Cuomo have quietly taken steps to form a new super PAC intended to boost his candidacy for mayor of New York City should he enter the race, according to email correspondence and two people familiar with the planning.

The planning for a super PAC is being guided by one of Mr. Cuomo’s most loyal advisers, Steven M. Cohen. His involvement and the advanced nature of the group’s discussions offer perhaps the strongest indication yet that the former Democratic governor, who is officially undecided on a campaign, is laying the groundwork for a potential last-minute entrance.

The email messages, obtained by The New York Times, included a detailed discussion of what to name the super PAC. The options included “Fix NYC,” “Bring Back NYC,” “Reform Our City” and other variations on themes that Mr. Cuomo has discussed in recent public appearances and opinion articles.

The emails, which have not been previously reported, showed that two former aides to President Trump were involved in planning discussions as of mid-January: the financier Anthony Scaramucci and a member of a consulting and lobbying firm where another Cuomo ally, Charlie King, is a partner. That firm appears to no longer be active in the discussions.

A super PAC could be enormously helpful to Mr. Cuomo, especially in an abbreviated sprint to the Democratic primary in June. Unlike candidates’ campaigns, super PACs are allowed to raise and spend unlimited sums of money from wealthy donors, so long as they do not coordinate with the declared candidates. They played a pivotal role in the 2021 race that made Eric Adams mayor.

Rich Azzopardi, a spokesman for Mr. Cuomo, declined to comment for this article. He has repeatedly said in recent weeks that Mr. Cuomo, who resigned as governor in 2021 following sexual harassment allegations that he denies, has yet to make a final decision about entering the race, which would pit him against Mr. Adams and a half-dozen other Democrats.

Mr. Cuomo, 67, is facing an unusually complicated decision. Mr. Adams is scheduled to stand trial in April on federal corruption charges, and polls suggest Mr. Cuomo would quickly supplant him as the front-runner. But if the Justice Department follows through on dropping the charges against Mr. Adams in the coming weeks, the mayor could get a new breath of political life.

Mr. Cuomo must decide whether to enter the race with enough time to raise money and collect the necessary petitions before they are due on April 3.

For now, he has kept an unusually low profile amid the uncertainty, even as his potential rivals have already started attacking him as a presumed candidate. Behind the scenes, though, he and his allies have taken increasingly concrete steps to assemble campaign machinery that he could quickly set into motion.

He has conducted public opinion polling, increased outreach to prominent New York politicians and met with the leaders of several influential labor unions. Several people involved in those conversations said that Mr. Cuomo had taken pains to avoid stating directly that he was planning to challenge Mr. Adams, but had stressed the need to forcefully address issues like crime and homelessness.

Rumors about the formation of a pro-Cuomo super PAC, also known in New York as an independent expenditure committee, have circulated for weeks. But the emails obtained by The Times are the first evidence that planning is underway.

There is no indication that the nascent group has begun soliciting pledges from donors, or if it is the only such group being formed. But given Mr. Cuomo’s long relationship with real estate developers and other deep-pocketed donors, a super PAC supporting him would have the potential to raise millions of dollars that could swamp potential rivals.

It is no surprise that Mr. Cohen would play a large role in a pro-Cuomo super PAC. A Democrat and former top deputy once referred to as Mr. Cuomo’s “right-hand man,” Mr. Cohen is well versed in the former governor’s favored campaign style and well connected in New York politics and business circles.

When an operative involved in the planning sent an email on Jan. 13 to solicit feedback on “NYC IE Naming Opportunities,” Mr. Cohen responded within minutes, rejecting one of the proposed names by citing an initiative that dated back to Mr. Cuomo’s father’s time as governor.

“I’m not a fan of Rebuild New York. It already exists and has been used repeatedly,” he wrote. “Indeed, it was Mario Cuomo’s Thruway bond initiative.”

It is less clear if other people included on the Jan. 13 emails remain involved in Mr. Cohen’s initiative.

Jennifer Cunningham, a Democratic political strategist who helped Mr. Cuomo pass legislation legalizing same-sex marriage, did not immediately respond to a request for comment on her role in the exchanges.

Two of the participants work for Mercury Public Affairs, a bipartisan consulting and lobbying firm where Mr. King is a partner. A third, Craig Engle, a partner at the law firm ArentFox Schiff, represents Mercury.

Mr. King was not included on the January email exchanges, though Politico reported around the same time that he was expected to play a prominent role in any Cuomo campaign. Mr. King declined to comment for this article.

John Gallagher, the firm’s president, said it was no longer involved in the super PAC planning. “Weeks ago, members of our D.C. office briefly discussed and then decided against pitching our firm to be involved in an independent expenditure committee involving the New York City mayor’s race,” he said.

Still, the inclusion — even temporarily — of several Republican lawyers and operatives in the email discussions could provide an attack line for the other Democratic mayoral candidates, most of whom are to the left of Mr. Cuomo, a moderate.

For example, the emails indicate that Mr. Engle, a prominent Republican campaign finance lawyer who helped dismantle fund-raising limits on super PACs in New York, weighed in on potential names.

In the email exchange, Mr. Engle also opposed naming the PAC “Rebuild NYC,” writing that it “sounds too construction oriented, whereas the problem we are solving is much broader than that.”

He also alluded to potential themes for Mr. Cuomo’s candidacy as he rejected another proposed name, “Lift NY.”

“Lift is not a hard-edged political advocacy word, but it does work with a lot of messages (subway, crime, cops),” he wrote.

Mr. Engle had no immediate comment.

Another member of the Mercury team included on the emails was Bryan Lanza, a Republican operative who worked for Mr. Trump’s 2016 campaign and first transition team. He has no known ties to Mr. Cuomo.

Mr. Scaramucci, the Long Island financier who served briefly as Mr. Trump’s communications director before turning against him, has his own longstanding relationship with Mr. Cuomo. He served as the finance chairman of a “Republicans for Cuomo” group during the politician’s 2010 campaign for governor, and was the first guest on his short-lived podcast after he resigned as governor.

Mr. Cuomo potentially has other funds from his time as governor that he could draw on directly for a campaign. His state account reported having $8 million in cash in January.

An analysis by Reinvent Albany, a government watchdog group, found that Mr. Cuomo would most likely be able to transfer about $1 million to a mayoral campaign if he participated in the city’s public matching funds program, under the program’s rules. If he did not participate, that figure would rise to around $2 million.

John Kaehny, the executive director of Reinvent Albany, said he expected that Mr. Cuomo’s rivals would almost certainly seek to challenge whether any super PAC was fully independent, given Mr. Cohen’s role. But he warned that the city’s slow enforcement process could allow the former governor or other candidates to effectively “make an end run” around campaign finance rules.

“That allows someone like Cuomo to use all the advantages of the independent expenditures, like unlimited and hidden spending, to get elected and beat the clock against enforcement,” Mr. Kaehny said.