Jeb Bush and Marco Rubio upped their attacks against each other on Thursday, as the two seek to outperform one another in the New Hampshire primary next Tuesday in hope to become the Republican establishment’s choice for president in 2016.

The issue for debate was a pro-Israel bill Rubio recently helped pass in the Senate.

On Thursday, Rubio pushed back against the attacks leveled against his inexperience and lack of accomplishments. “I’m proud of what I done in public service,” Rubio said, listing his legislative accomplishments, including imposing additional sanctions on Hezbollah, a measure that passed the Senate in November. The bill authorizes sanctions on international financial institutions that knowingly engage in business with Hezbollah and its enablers. It also identifies the organization’s satellite and internet providers that facilitate its messages to the al-Manar Hezbollah television station.

Jeb Bush’s campaign rushed to dismiss Rubio’s signature on the bill to impose sanctions on Hezbollah, noting that he didn’t even show up to vote on the Senate floor. (The measure passed by unanimous consent). Rubio was in New York City for a multi-dollar fundraiser hosted by Phil Rosen. His amendments were offered by Sen. Steve Daines on his behalf.

“When he was asked what his main accomplishments were, one of them was dealing with Hezbollah, which was a 93 to nothing vote that he didn’t go to,” Bush said on Thursday. “You know, this is not real. In Iowa, one of our last events was with Chuck Grassley, the guy has not missed a vote for 22 and a half years. He probably has a list of accomplishments in service to the State of Iowa and to this country that is pretty real. Marco doesn’t have it.”

“Marco Rubio has had opportunities to lead time and again as a U.S. Senator, but he’s cut and run. Now, he wants to be President of the United States. We need a Commander-in-Chief with the record and results to lead our nation forward, and that’s Jeb Bush,” A Bush spokesperson, Matt Gorman, told Business Insider in an email on Thursday.

A UMass/7News tracking poll shows Rubio in second place in New Hampshire with 15 percent of likely voters’ support. Jeb is in fourth place with 8 percent.