With a week left before the state Assembly is expected to reconsider Mayor Bloomberg’s congestion pricing bill, opponents of the plan are highlighting inconsistencies they say make the bill “un-enactable.”

Assemblyman Richard Brodsky, a Democrat of Westchester, today is scheduled to release a 25-page report that shows how the bill before the legislature differs significantly from the road tax proposal Mr. Bloomberg outlined in his 2030 plan for the city.

While Mr. Bloomberg has assured Manhattan vehicle owners that they would likely not pay to move their cars within the tolled zone to comply with alternateside parking rules, Mr. Brodsky charges that such an exemption is not in the bill. The legislation also doesn’t identify locations or standards for residential parking permits that have been put forward as a possibility for neighborhoods surrounding the tolled zone.

While Mr. Bloomberg has said the funds collected from charging drivers in Manhattan would be used to fund capital improvements to the mass transit system, Mr. Brodsky said, “That’s not in the bill.”

Mr. Brodsky is pushing an alternative he calls “congestion rationing,” where certain license plates would be allowed to drive at designated times. He says this would eliminate class issues that could arise if the city charged motorists to drive.

A spokesman for Mr. Bloomberg, Stuart Loeser, said the administration could not comment on the specifics of a report it hadn’t yet seen. “If Albany fails to act in the coming days, the half-billion dollars Washington is offering us for a pilot program will go to another city or another state, period,” Mr. Loeser said.

A two-minute ad paid for by the Coalition to Keep NYC Congestion Tax Free is also scheduled to debut today at the Web site YouTube.com. The ad shows images of straphangers packed like sardines on the 4, 5, and 6 subway lines during rush hour. It quotes the president of New York City Transit, Howard Roberts, saying that the trains are operating at capacity and that there is no room for more passengers. Mr. Roberts later retracted the statement, saying the system could handle the expected 100,000 additional riders that would flood its turnstiles if more drivers switched to mass transit. The ad ends with the message: “There has to be a better way.”

Meanwhile, Mr. Bloomberg talked up congestion pricing on his weekly radio address yesterday. He is expected to travel to Washington tomorrow to push the Bush administration for federal funding to pay for the program.