SALEM — State Rep. John Keenan is attempting an "end run" around a public process by earmarking $15 million for a city parking garage in a state transportation program designed to encourage housing, bike paths and pedestrian walkways near MBTA stations, a state environmental group charged.

"It's an end run around a competitive process," said Carrie Russell, a staff attorney at the Conservation Law Foundation.

Keenan, a second-term Salem Democrat, has requested $15 million for a proposed 1,000-car garage at the commuter rail station, a project that the city has tried unsuccessfully to fund for more than a decade. He put the funding request into a $2.9 billion transportation bond bill currently before the Legislature.

Objections were raised because the funding is earmarked in a "transit-oriented development" program that has total proposed funding of only $20 million and whose guidelines limit expenditures to $2 million.

"The big problem is, first of all, it leaves only $5 million for the rest of the state," Russell said. "That's sort of scraps for the rest of the state."

Keenan strongly objected to the suggestion he has done anything wrong. He said he originally asked for $25 million for the garage from the bond bill and didn't specify the funding source. After talking to Rep. Charles Murphy, a Burlington Democrat and vice chairman of the legislative Transportation Committee, he said they agreed to seek the money from this program, which funds parking near transit stations.

"There's no such thing as an end run," Keenan said when told of the characterization by the CLF. "That's called legislation. My job is to deliver for my district. ... Nothing was done behind closed doors."

The transit improvement program, created from a 2004 bond bill, supports improvements within a quarter-mile of transit stations, according to the state Executive Office of Transportation. More than $10 million has been spent so far on a number of projects, including pedestrian walkways in Lynn and Chelsea, bike improvements in Boston's Chinatown, and public housing in Dorchester.

The Executive Office of Transportation has a committee that reviews requests for funding from around the state.

Russell said she is not objecting to the Salem garage, since parking improvements are allowed under the guidelines, but opposes any attempt to fund a project without a competitive review by the state.

"I think it's perfectly appropriate for (the Salem garage) to apply for the competitive funds and to go up against every other project in the state and be subject to the same criteria, so the best project will be funded," she said.

Keenan said he is not seeking preferential treatment and is only trying to get money for a public improvement that is even more needed now that plans are underway to build a $106 million state courthouse across the street. Parking for court employees would be designated in the garage.

The MBTA said it does not have any current funding for the Salem garage.

"I do not want to squeeze out any other legitimate project," Keenan said. "I'm just trying to make the case that I think this is a critical project for Salem. ... I'm not trying to box out any of my colleagues. I'm just trying to get my project funded."

Murphy, the legislative committee vice chairman, said he put the funding request into the bond bill at Keenan's request.

"A colleague approached me for some assistance," he said. "It was a legitimate project, and I assisted him."

Keenan said he and Mayor Kim Driscoll are investigating a possible public-private joint venture to build the garage, which had an estimated cost of $25 million several years ago. Keenan said he thinks the current budget would be closer to $35 million.

Keenan said that he expects this debate over Salem garage funding could be moot by the end of the week. He said this earmark, and others, likely will be dropped by the House Ways and Means Committee in order to create a "clean bill" and smoother debate.

"I don't think it's going to make it out of Ways and Means," he said.