''We are behind and I have acknowledge that. But we can win. It is difficult but we have to hold our nerve and our conviction and our belief not just in what we've done but what we plan to do,'' he said.

Ms Gillard is still ahead, 41 per cent to 39 per cent, but the gap has narrowed from 45 per cent to 33 per cent in the January 11-13 poll.

In the latest Newspoll, the Coalition leads Labor, 56 per cent to 44 per cent on a two-party-preferred basis.

Labor MP Nick Champion added that his party was united. ''Of course we're united. We're united around disability reform, around education reform. We're united around the Prime Minister's leadership,'' he told ABC TV.

During the caucus meeting, Ms Gillard also defended her surprise decision to call the election on September 14, more than seven months ahead of the polling day. She said that this meant that the government was now in the same position as many other state governments and that the election campaign had not begun as a result.

She hit back at criticism from within Labor that Ms Gillard had given away the tactical advantage of not naming the election date until the last minute. The Prime Minister explained there were only a limited number of election days and that by naming September 14, it had ended endless speculation about the polling date.

In Labor's first caucus meeting of the year, there was only one question to the Prime Minister, with one MP saying they thought NT Senator Trish Crossin had been treated unfairly in Ms Gillard's decision to support the preselection of Olympian Nova Peris.

Following the resignation as Chris Evans on Saturday, caucus elected Communications Minister Stephen Conroy, from the Victorian Right, as the new Senate leader and Finance Minister Penny Wong, from the Left, as deputy.