BOSTON (AP) - Republican Gabriel Gomez and Democrat Edward Markey are prepping for their final debate in Massachusetts' special U.S. Senate election.

The candidates are scheduled to go head-to-head in an hour-long debate Tuesday night at the studios of WGBH-TV. The debate is sponsored by a consortium of Boston media outlets. The match-up comes as Gomez is struggling to close a gap with Markey, who has held a modest lead in recent polls. Gomez has portrayed Markey as an entrenched Washington insider while Markey said Gomez is beholden to the national Republican agenda.

On Monday, both candidates weighed in on President Barack Obama's decision to begin arming rebels in Syria.

Markey offered cautious support for Obama's plan saying he also supports providing light arms to rebels battling Syrian President Bashar Assad as long as the CIA can guarantee the arms are going to "carefully vetted, pro-democracy insurgent groups."

"If we provide them with light arms I think that can be done in a way that could help to advance the goal of removing Assad from office," Markey told reporters.

Gomez, a former Navy SEAL, said that evidence of chemical weapons use shows Syria has already passed Obama's own "red line."

"The president has a range of other options available to him," Gomez said in a written statement. "I continue to support a no-fly zone and hope the president and our allies will consider taking this action."

Markey said he's reluctant to support a no-fly zone.

Markey is heading into the final stretch with more than a two-to-one fundraising advantage over Gomez.

Markey's latest campaign finance report shows as of June 5 he had nearly $2.3 million to spend compared to just under $1 million for Gomez.

The Federal Election Commission report also shows Markey has raised more than $7.8 million for the election, including more than $800,000 from political action committees.

Gomez has raised $3.3 million, including $170,000 from PACs. Gomez's total includes a $900,000 loan he made to his campaign.

The election is June 25.