When Mayor Bloomberg was running for re-election, he vowed not to raise taxes to finance his campaign proposals. At a mayoral debate, he told New Yorkers to “expect to see a continued focus on doing more with less,” and promised no tax increases through mid-2007.

Within a few days of his sweeping reelection, however, Mr. Bloomberg started talking about new taxes, specifically, renewing the commuter tax, which Albany eliminated from the city’s budget in 1999.

On Friday, Mr. Bloomberg suggested that reinstating an income tax on commuters would help close the city’s looming $4.5 billion budget gap.

“What we need is a commuter tax, and I fought for that a long time,” he told reporters at the Veterans Day parade, according to Newsday. “And we’ll continue to fight for a commuter tax. That’s the way to solve some problems.”

On Monday, he expanded on that idea: “An awful lot of the people in the suburbs come in and work in this city, and the reason they have jobs here is because of all the services that the city provides. It’s not unreasonable to ask them to pay part of the cost of those services. After all, in every meaningful sense, whether they work here or just live nearby, they do get a lot of value.”

He acknowledged that reinstating the tax, which would yield about $450 million in new revenues, would “be a difficult political lift.”

Mr. Bloomberg hasn’t yet sent lobbyists to Albany to push for the tax, but already legislators, including the majority leader in the State Senate, Joseph Bruno, have vowed to fight the tax.

Taxation authorities say the mayor’s remarks could be an omen of higher taxes to come.

“If the mayor seriously embraced the commuter tax, that would be a bad sign for the future because it would probably mean a tax increase for city residents. That’s what it meant the last time he did it,” the Manhattan Institute taxes guru, E.J. McMahon, said. “I get the sense that he has not ruled out increasing taxes. He never made an explicit promise to avoid it. He made it pretty clear that he is not ruling anything out.” Moreover, Mr. McMahon said, the commuter tax would not be a good thing for New York.

“A commuter tax is another way of saying a wage toll. It’s basically a way of hindering job growth in the city by firms that employ large numbers of commuters,” he said.

Other commentators on city government and finance had more positive impressions of the commuter tax, but even they doubted whether Albany would jump at an election-year chance to boost taxes on suburban swing voters.

“I think the commuter tax is a good thing. I think it’s the principle of daily commuters paying their share of city services,” a professor of public administration at Columbia University, Steven Cohen, said. But, he added, “There’s no political advantage to the people running the Legislature to let Bloomberg have his way” on this tax.

Mr. Cohen said in the absence of other ideas for plugging the hole in the city’s budget, the mayor might have to find new revenue sources, rather than making strategic cuts: “There are very few frills left in New York City’s budget after 30 years of fiscal duress.”

A spokesman for the mayor, Jordan Barowitz, said the mayor did not make any no-tax pledges during his campaign, except when it came to the eight proposals he issued before Election Day.

“He never said ‘I swear I won’t raise taxes in the second term,’ ” Mr. Barowitz said. “He never said that.”

Mr. Barowitz also pointed out that Mr. Bloomberg has backed a commuter tax since 2001, when he was first campaigning. He also mentioned his support for it at the second debate in this year’s campaign.

The mayor is expected to clarify his budget priorities – and whether they consist more of cutting or taxing and spending – in mid-January, when he releases his preliminary budget proposal.