Amy Schumer has switched sides in New York's Governor election race after declaring she couldn't vote for fellow actress Cynthia Nixon.

The Trainwreck star took to Instagram on Tuesday (11Sep18) to reveal she wouldn't be voting for the Sex and the City star over incumbent Andrew Cuomo, because she didn't believe the screen star would "know what the heck to do" in office.

Amy explained she loves the actress, but doesn't think she would be an effective leader because she doesn't have the connections Cuomo does.

"Thursday we vote. Everyone! It’s not cute to not vote anymore. I’ll tell you who I’m voting for honestly," she wrote. "For gov: cuomo... Reason: Andrew isn’t my fav dude But he’s good gov (sic). I wanted to vote Nixon, but sadly, i don’t believe she would know what the heck to do. She needs to be able to pressure the state legislature in stuff but I don’t believe she has enough connections upstate. But I love her and think if anyone is inclined voting Nixon is cool."

Amy clearly changed her mind at the polls, posting a photo of herself on Instagram outside her polling site, with her dog.

"We voted," she wrote. "And we voted for @cynthiaenixon couldn’t help it... voted with my heart thanks to the women who took their time to talk to me about it. When someone disagrees with you be patient and have a conversation. It's most productive."

Polls close at 9pm local time and results should be released overnight.

Cuomo, who has been New York's Governor since 2011, is a heavy favourite.