A senior government minister in Australia has announced that her lesbian partner is pregnant.

Finance Minister Penny Wong said in a statement Tuesday that her partner, Sophie Allouache, had conceived through in-vitro fertilization and is expecting her first child in December.

The announcement comes as pressure mounts on Prime Minister Julia Gillard to support overturning her center-left Labor Party's ban on gay marriage. The policy change will be voted on its annual national conference in December.

Tasmania state's Labor branch at the weekend became the seventh of Australia's eight state and territory branches to pass a motion supporting gay marriage.