Sydney: The race for Australia’s Labor leadership narrowed to two contenders on Monday with ex-treasurer Chris Bowen bowing out as the vanquished party faced a rocky rebuilding from years of turmoil.

The tussle to replace Kevin Rudd and become opposition leader looked set to involve Anthony Albanese, former deputy prime minister, and education minister Bill Shorten, after Bowen announced he would not be standing, as did party veteran Wayne Swan.

Labor faces the difficult task of rebuilding after a comprehensive election defeat by Tony Abbott’s Liberal-Nationals as voters punished them at the ballot box for years of in-fighting, which saw two leadership coups in as many terms in office.

With the election of Abbott, Australia has now had three prime ministers in little more than three months, following Rudd’s ouster of Julia Gillard in June and his own dispatch at the weekend by voters. Gillard had toppled him just ahead of the 2010 elections.

Rudd stood aside after Saturday’s defeat, saying the Australian people “deserve a fresh start”.

“We now need to best determine how we can be the most effective, the most united, the most focused opposition that we possibly can be, to hold the new Abbott government to account,” Bowen told reporters.

“We need to acknowledge and learn from the message the Australian people gave us on Saturday, that they want a Labor party united, stable, focused on them, not on ourselves.”

Shorten said on Sunday he was “genuinely undecided” about whether to run and Albanese would not say one way or another.

There are also questions about whether the decision will be put to a vote of the full Labor party membership under reforms brought in by Rudd after he deposed Gillard in a bid to stop the endless leadership spills.

“I think if there are two candidates then clearly it must go to a vote of the full party membership. We’ve adopted that rule, it’s an important rule,” said Bowen.

If only one person ultimately stood Bowen said the party ought to take that as a sign “consensus” had been reached.

“The [party room] adopted these rules and these are the rules that should apply. Obviously I’m a strong supporter and advocate of party reform and I think that should be an ongoing process,” he said.