Bill Shorten today said he wanted unity to return to the Australian Labor Party.

He wanted to "rule a line under the divisions of the Rudd and Gillard era", for everyone in his party to be nice to each other and for the plotting and conniving to end.

As he announced his wish to become the new Labor leader, Mr Shorten referred to the disunity that is generally regarded as a major cause of Labor's election rout.

And he accepted his part in it, suggesting it's acceptable to be disruptive if your intentions are as honourable as his were.

"In making hard decisions, what's motivated me is how to make the Labor Party the most competitive force it can be in Australian politics," he said.

"It is very clear that I, along with all members of the caucus, should accept some responsibility for the last few years.

"Decisions were hard. But I have always acted with the best interests of the Labor Party and the nation at stake."

Mr Shorten made his opening bid for the top job with sincerity and conviction.

He delivered his words thoughtfully and calmly, took a shot at Mr Rudd and later praised him and Ms Gillard.

Mr Rudd, the first prime minister against whom he plotted, had done a good job in the campaign, his efforts ensuring the return to parliament of as many Labor MPs as possible.

"I will acknowledge that forever," Mr Shorten said.

In line with his call for positivism, Mr Shorten spoke pleasantly, if not glowingly, about Ms Gillard, whose demise he worked for this year.

"I am grateful for the work Julia Gillard did in a minority government. She led us through some difficult times."

The announcement came as Kevin Rudd today handed the keys to the lodge over to Tony Abbott.

Mt Abbott said his daughters would live there also, and joked they would do so until they were married.

Kevin Rudd quipped, "I know that feeling."