Cheney, one of former Vice President Dick Cheney's two daughters, issued a statement clarifying her stances on the controversial issues and accusing her GOP opponent, incumbent Mike Enzi, of creating confusion about her positions.
"I am strongly pro-life and I am not pro-gay marriage," Cheney said, adding that she believed "the issue of marriage must be decided by the states, and by the people in the states, not by judges and not even by legislators, but by the people themselves."
Cheney, whose sister Mary is a lesbian, said Enzi supporters conducted a deliberately misleading "push poll" that stated she supported gay marriage and abortion.
"The people of Wyoming deserve an honest campaign," she said. "They should not be subject to the kind of dirty tricks this push poll represents."
ABC News said Enzi's camp responded with a statement denying he was behind the poll.
"For Liz Cheney to assert otherwise, without any proof whatsoever, shows more about her campaign than Mike Enzi's," Enzi campaign spokesman Coy Knobel said.