Mayor Bloomberg is criticizing a proposal to suspend the federal gas tax during the summer months, a plan backed by senators Clinton and McCain, as “about the dumbest thing I’ve heard in an awful long time, from an economic point of view.”

Speaking to reporters yesterday in Manhattan, the mayor said: “We’re trying to discourage people from driving and we’re trying to end our energy dependence and incidentally we’re trying to have more money to build infrastructure. All three of those things fly in the face of giving everybody 30 bucks a year.”

Both Mr. McCain and Mrs. Clinton suggested this week that the federal government temporarily do away with its 18-cents-a-gallon gas tax and 24-cents-a-gallon diesel tax as a relief measure to counter high oil prices. Senator Obama came out against the plan, which he described as a “gimmick” to draw votes, saying the overall savings for most Americans would be limited and that the money was needed by the federal government to maintain its infrastructure. Ms. Clinton has run ads in North Carolina and Indiana, both of whose primaries are on May 6, criticizing Mr. Obama’s stance on the issue.

Mr. Bloomberg said yesterday he thought, “In this case, Obama had it right.”

Asked about a proposal by the state Senate majority leader, Joseph Bruno, to apply a similar policy to New York state’s gas tax — about 33 cents a gallon — over the summer, Mr. Bloomberg repeated his objections.

“I just do not think that it is intelligent policy and it’s not a good energy policy,” he said. He added that he has not yet discussed the issue with Mr. Bruno.

Governor Paterson has expressed reservations about suspending the gas tax, saying he is not sure the money would ultimately reach consumers and that giving up revenue would make balancing the budget more difficult.