A lesbian minister in Australia has announced that her partner is pregnant with their first child.

Penny Wong, the finance minister, said her partner Sophie Allouache conceived through donor insemination and expects the baby in December.

In a statement, she thanked the biological father “for giving us the opportunity to raise a child together”.

She added: “We have chosen to make this statement about Sophie’s pregnancy as we understand there may be public interest due to my position.”

The news has reignited the debate about gay marriage in Australia.

Ms Wong was criticised last July for refusing to give her views on the issue. But in November, she introduced a motion in favour of same-sex marriage.

She said: “I will be advocating for our party to support equality including to in relation to marriage or same-sex couples and I do so because I have a deeply held commitment to equality.”

Australian prime minister Julia Gillard gave her congratulations to the couple but restated her anti-gay marriage views.

She told reporters: “Penny Wong is a colleague of mine, she’s also a very long-term friend, so I’m very pleased for Penny and her partner Sophie as they look forward to a new baby and the next phase of their lives.

“Clearly there are strong views about same-sex marriage in the community. I’ve made my views clear.”