With less than one week to go in the Massachusetts special election for the U.S. Senate seat vacated by Secretary of State John Kerry, candidates Republican Gabriel Gomez and Democratic Rep. Ed Markey, squared off in their final debate Tuesday at WGBH in Brighton.

The tone was heated.

In one sharp exchange, Gomez asked Markey if he supported term limits. It was one of many digs at Markey’s 37 years in Congress.

Markey shot back that Gomez got help from some veteran politicians himself:

"Mr. Gomez, you just had John McCain campaigning for you three weeks ago," Markey said. "Did you ask John McCain to leave the Senate? No, you did not."

"Yes, I did," Gomez replied.

"No, you did not," Markey shot back. "You did not tell John McCain he does not belong in the Senate any more as you were praising him at that press conference. That did not happen."

Markey repeatedly pressed Gomez for more information about clients he worked for at the private equity firm Advent International.

"He still hasn't released who his clients were, who he worked for as he brags about his business career," Markey said. And I do believe that the people of Massachusetts have a right to know."

Gomez responded that President Barack Obama was a client at Advent International. The president’s pension fund from his years as an Illinois lawmaker is invested with the company.

Gomez attacked Markey as an ineffective career politician while describing himself as bipartisan.

"Only one of us is actually bipartisan, by experience, to actually go down there and work across the aisle to get both sides to come together," Gomez said. "If you go down there, Congressman, nothing changes. It's going to be the exact same vote."

Gomez has been trying to appeal to appeal to independents and conservative democrats.

But Markey said Gomez is the typical conservative.

"Mr. Gomez says he's running as a new kind of Republican, but it's actually the oldest, stalest Republican ideals."

The election is on June 25.