His own party kicked him out two years later after a series of gaffes, unpopular policy decisions, and shocking polls showing he was leading them to defeat.

But Mr Abbott isn't dwelling on the negatives.

"Today is the fifth anniversary of the election of the Abbott government. It's a good government, getting better!" Mr Abbott tweeted on Friday.

In a week's time it will be the three-year anniversary of Malcolm Turnbull's spill to take over from Mr Abbott, which led to a narrow coalition victory in 2016.

Prime Minister Scott Morrison praised both his predecessors for their roles in winning the last two elections.

"I pay tribute to Tony Abbott who led us back into government, and Malcolm Turnbull and Julie Bishop, who was the deputy (leader) over that entire period," Mr Morrison told Triple M radio in Melbourne.

Mr Morrison said he was proud to have been a part of what the coalition government had achieved.

"We've got a lot of runs on the board, but ... I need to explain to Australians why we're doing things so that in the future, they'll know how I make decisions," he said.

Defence Minister Christopher Pyne was asked why Australia has a new prime minister, and he said the question was a good one.

"It's yet to be answered by those people who thought there needed to be a change to the leadership," Mr Pyne told Sky News.

Mr Morrison's office sent out a list of achievements made under the Abbott-Turnbull-Morrison governments, including more than one million new jobs, a booming economy, and a budget coming back to surplus.

Australian Associated Press