A new campaign pushing back against cuts to the MBTA maintenance workforce launched Monday with a protest outside the Transportation Building ahead of a T board meeting.

"Hundreds of workers" must be hired in order to "put the MBTA back on the tracks," MetroBTC secretary-treasurer Brian Doherty said.

Through public records requests, the Safe Transit Now campaign identified a 17.5 percent reduction in a basket of employee groups - electricians, sheet metal workers, painters, pipefitters and carpenters, among them - from 407 workers in 2014 to 336 last year.

"Governor Baker and his administration have slashed the MBTA workforce every year," Massachusetts AFL-CIO president Steve Tolman told a crowd on the Stuart Street sidewalk. "... And then he expects the trains to continue running at the same pace. It just won't happen. It makes no sense."

The administration pointed over the weekend to Baker's $18 billion transportation borrowing plan, which the House amended and passed last week, along with Baker's proposed addition of a safety expert to the T's governing board and his request for money to hire staff. The Legislature has agreed to $32 million out of that $50 million request.

During Monday's board meeting, MBTA General Manager Steve Poftak said the T is now adding headcount "at a rate that is unprecedented within recent memory. "Through March, the MBTA has already hired more staff this fiscal year than in each of the past four years, including 84 employees in major engineering and maintenance roles, Poftak said. Officials expect to bring nearly 1,000 employees on board this year.

"I want to be clear," Poftak said. "The word 'cuts' keeps being used. We are hiring far and above where we were before."