Sen. Mark Pryor's vote for a government funding bill that included health care subsidies for members of Congress and their staff is now being used as an attack line by his re-election challenger.

In Rep. Tom Cotton's first television ad of his Arkansas Senate campaign, unveiled Monday, a narrator hits Pryor, D-Ark., for supporting a government funding measure without other provisions, including the health care subsidies, attached.

"Mark Pryor cast the deciding vote to make you live under Obamacare," a narrator says. "But Pryor votes himself, and everyone in Congress, special subsidies so they're protected from Obamacare."

The vote was one in a series by Senate Democrats to block attempts by House Republicans to attach their own policy priorities to a measure needed to keep the government running. The fight over that effort shut down the government.

A spokesperson for Pryor's campaign called the ad "blatantly false" and "a weak attempt to distract from" some of Cotton's controversial votes.

Each side in the Arkansas race, among the most competitive of the 2014 elections, has tried to spin the government shutdown to its advantage. While Cotton, R-Ark., has insisted that Democrats like Pryor refuse to negotiate with Republicans, Democrats have tried to tie the impasse directly to House Republicans, including Cotton.