Atheists have accused the Brumby Government of discriminating against them by refusing to fund the movement's global conference in Melbourne, but giving $2 million to a religious conference.

The Parliament of the World's Religions begins on December 3 at the new Melbourne Convention and Exhibition Centre and has also received $2 million from the Federal Government and $500,000 from the Melbourne City Council.

Premier John Brumby launched the event this morning.

The Atheist Foundation of Australia says it approached all three levels of government for a total of $270,000 for its conference, to be held at the same venue early next year, but has received no funding.

"This is a world-class event with world-class academic and intellectual speakers," foundation president David Nicholls said.