Former Australian foreign minister Kevin Rudd announced Friday that he will challenge Prime Minister Julia Gillard for leadership of their Labor Party in a ballot on Monday.

Rudd told a news conference that the prime minister had lost the trust of the Australian people and starting Monday he would start to restore that trust.

Ms. Gillard called Thursday for her party to vote on its leadership, seeking to resolve an ugly dispute with Rudd, whom she ousted as prime minister in June of 2010.

Ms. Gillard told reporters Thursday that she believed it was in the best interests of her Labor Party and of the country to put an end to speculation that Rudd was planning an internal party coup. He resigned as foreign minister on Wednesday, saying he could not continue without the prime minister's support.

“I have decided that at 10 a.m. Monday morning a ballot for the Labor leadership will be conducted. Following Kevin Rudd's resignation yesterday I have formed this view that we need a leadership ballot in order to settle this question once and for all.”

The ill feeling between the two goes back to 2010 when Ms. Gillard toppled Rudd. It was a political humiliation for Rudd, who was eventually appointed foreign minister.

Following Rudd's ouster, Ms. Gillard led the Labor Party into elections in which it barely squeaked back into power, with the support of a handful of independent members of parliament.

Recent polls have shown the Labor Party trailing far behind the opposition Liberal Party, but show Labor would perform better with Rudd as its leader.

Ms. Gillard insists she has the support of her parliamentary caucus and has expressed confidence she would survive any attempt at an internal coup.

Australia's next national elections are scheduled for 2013.