FILE PHOTO: Australian Prime Minister Malcolm Turnbull speaks at a news conference after a meeting with NATO Secretary-General Jens Stoltenberg at the Alliance's headquarters in Brussels, Belgium April 24, 2018. REUTERS/Francois Walschaerts/File Photo

SYDNEY (Reuters) - Australian Prime Minister Malcolm Turnbull declared the leadership of the government vacant on Tuesday, a spokesman said, setting up a challenge to his position after weeks of speculation and falling opinion poll numbers.

“The prime minister declared the position is vacant,” a spokesman for Turnbull said by telephone. “Now there’s a call for nominations.”

Sky News said Turnbull will stand for the leadership again and would be challenged by Home Affairs Minister Peter Dutton.