Washington (CNN) Republican Sen. Susan Collins, a supporter of abortion rights who cast a critical vote to confirm Justice Brett Kavanaugh, said in an interview with CNN that despite his vote in a recent abortion access case, she did not believe Kavanaugh would ultimately vote to overturn Roe v. Wade.

"I have always been concerned about preserving Roe v. Wade" Collins said Monday, adding that Kavanaugh had given her assurances during his confirmation process that the landmark opinion was safe.

"He said under oath many times, as well as to me personally many times, that he considers Roe to be 'precedent upon precedent' because it had been reaffirmed in the Casey v Planned Parenthood case," Collins added, dismissing any criticism of her as partisan politics.