Lexington attorney Cal Cunningham and Secretary of State Elaine Marshall took park in a televised debate in Raleigh.
The two tackled several issues including the oil spill in the Gulf and a proposal to drill off the North Carolina coast.
"I would not support ... we do need stricter safety regulation ... I look at the goo covered birds and that tears my heart out," Marshal said.
"We have to hold BP to a high standard ... end of the tax breaks ... all of the costs," Cunningham said.
It is their first one-on-one debate since they advanced to the runoff following the May 4 primary. Marshall finished first and Cunningham second, but Marshall did not get enough votes to prevent a runoff.
Early voting has begun for the June 22 runoff. The winner takes on Republican incumbent Richard Burr in November.