Unless the state comes to the rescue of the MBTA, riders may be hit with a 30 percent fare hike and half the level of service on weekends and during off-peak hours, top state transportation officials warned Monday.

A hike of that size would push a $1.70 subway ride to $2.21, higher than New York's current $2.

The cuts are likely, MBTA General Manager Daniel Grabauskas said, if lawmakers don't act to fill a looming $161 million hole in the MBTA's fiscal 2010 budget. About 30 cents on every dollar in that proposed budget, set to go before the MBTA's board on Thursday, will be spent on debt service, an increase from the current 26 to 27 cents, Grabauskas said.

"I didn't think we created this MBTA to be a brokerage house, but that's what we're turning into," he said.

Hundreds of thousands of people take 1.3 million rides per day on MBTA trains and buses, according to Grabauskas, and Boston is one of three major cities along with New York and Washington, D.C, in which more than 50 percent of the workforce commutes in via public transportation. If a revenue hike put a crimp in the T's record ridership in recent months, "It would be my biggest regret," he said.

Secretary of Transportation James Aloisi endorsed Grabauskas's assessment and told the News Service he expected to cobble together the necessary 81 votes in the fractious House to pass the governor's transportation finance plan, which he expects to stave off the worst of the service cuts. The governor's plan would hike the state gas tax 19 cents per gallon, six cents of which would plug the T's budget.

Asked about the administration's vote count on its bill, Aloisi, in an interview, said, "I don't think we're losing votes. I think we're trying to build a consensus." Aloisi said he doesn't think achieving that consensus among lawmakers "will be tough at all" because the bill includes a "historic" provision to return 75 percent of all gas tax revenue to the regions where it was collected.

Asked why voters contemplating higher gas taxes should be assuaged by promises of regional equity, Aloisi said, "We're going to put it into law. It's not about saying 'trust us' any more."

Aloisi's pointed comments in recent weeks have angered powerful figures on both sides of the aisle - including Senate President Therese Murray, whose mantra "reform before revenue" he shrugged off as a "meaningless slogan" in a meeting with lawmakers.

He said he hopes his "passion" for the issues doesn't get in the way of passing the governor's proposal.

"I'm passionate about these things and I believe in them," he said. "Sometimes I'm misquoted and sometimes I'm not. I have said from the beginning I have said I believe the Legislature and the members of the Legislature are my comrades."

As for the Senate president? "I'm hoping to speak with her soon," he said. "I have a lot of respect for the Senate president. I've known her for years and we've been very good friends for years. We're going to remain friends as far as I'm concerned because I respect her and I respect her role."

Aloisi and Grabauskas appeared at the foot of the State House on a dreary Monday to join MassPIRG, the T Riders Union and other backers of public transportation for a bake sale intended to highlight the T's need for revenue. Backers of the gas tax proposal held signs such as, "Cut Cake, not T services" or "Bail out the MBTA. Get a cookie."

The T Riders Union and Grabauskas heaped praise on Gov. Deval Patrick for proposing the gas tax increase, which Grabauskas said was "courageous" during a time of economic distress.

Patrick is spending the week vacationing in Jamaica. His proposal is competing with a Senate proposal that does not include a gas tax, and one key lawmaker - Transportation Committee co-chair Joseph Wagner - has effectively declared that his 19-cent hike won't pass. A handful of influential business groups have gotten behind a 25-cent gas tax increase, arguing that it is the only way to get the state's aging transportation system back on solid footing.