Updated

Prime Minister Julia Gillard has called for a leadership ballot Thursday as her party faces the growing prospect of a sound election defeat later this year.

She said the ballot of a leader and deputy leader of the Labor Party would be held in the afternoon, hours after a senior minister called on her to hold a vote.

Minister Simon Crean said he would nominate as the deputy and wanted former prime minister Kevin Rudd to stand as the candidate for the top post.