Cynthia Nixon has insisted being gay was her "choice".

The actress has sparked outrage among some homosexuals by claiming her sexuality was a choice rather than a genetic development.

The Sex and the City star came out in 2004 and is engaged to long-term partner Christine Marinoni.

"I gave a speech recently, an empowerment speech to a gay audience, and it included the line, 'I've been straight and I've been gay, and gay is better.' And they tried to get me to change it, because they said it implies that homosexuality can be a choice. And for me, it is a choice," Cynthia was quoted by celebrity blogger Perez Hilton. "I understand that for many people it's not, but for me it's a choice, and you don't get to define my gayness for me. A certain section of our community is very concerned that it not be seen as a choice, because if it's a choice, then we could opt out. I say it doesn't matter if we flew here or we swam here, it matters that we are here and we are one group and let us stop trying to make a litmus test for who is considered gay and who is not."

Cynthia claims she wasn't born homosexual, but that this doesn't make her sexuality any less real.

The star has two children from her 15-year relationship with ex-boyfriend Danny Mozes. Last February, Christine gave birth to their son.

The 45-year-old feels offended when people suggest she was born gay but simply didn't realise her preference for women earlier.

"Why can't it be a choice? Why is that any less legitimate? It seems we're just ceding this point to bigots who are demanding it, and I don't think that they should define the terms of the debate," she said. "I also feel like people think I was walking around in a cloud and didn't realise I was gay, which I find really offensive. I find it offensive to me, but I also find it offensive to all the men I've been out with."