Addressing the Victorian Fabian Society last night, Butler warned Labor was “treading water” with falling numbers and only 50,000 members out of a country nearing 25 million.

Butler, the federal MP for Port Adelaide and one of Premier Jay Weatherill’s closest confidantes, said the rank and file of the party needed to be given greater power.

“I’m sorry to say that ours remains a party that gives ordinary members fewer rights than any other labour or social democratic party I can think of,” he said.

Butler said many of the reforms discussed at the national conference in 2015 have been blocked by factional leaders.

“It is time to issue a strong call for the conference in Adelaide this July to grasp the nettle and to give ALP members the range of democratic and participatory rights that members of our sister parties across the world take for granted,” he said.

Butler also pushed for a new category of member, called a registered supporter, who could vote in leadership ballots.

The president cited British Labour’s recruitment of 35,000 new members in four days after the 2017 election, taking its body up to 550,000.

“Our members here in Australia are hardworking, motivated believers in the Labor mission but as a group we are not representative of the broader Australian population,” he said.

While Labor can come together for election campaigns, there isn’t the army of supporters to organise beyond them and it can’t compete with the likes of GetUp, Butler said.

He was scathing of recent factional manoeuvring in Victoria which he described as “backroom buffoonery” that “does not reflect a healthy party organisation”.

Butler’s speech was seized on by the state Liberal Opposition, who face a state election showdown with Weatherill’s Labor and Nick Xenophon’s SA Best in March.

“Today’s statements from Left faction powerbroker Mark Butler and key ally of Premier Weatherill amount to open warfare with the dominant Right faction of the South Australian Labor Party,” said deputy Liberal leader Vickie Chapman.

“This factional brawling a matter of weeks out from the state election demonstrates why the Labor Party is not fit to continue governing South Australia.”

Weatherill insisted Butler’s comments did not relate to South Australia.

“Mark’s remarks specifically reference NSW and Victoria and not South Australia,” he said in a statement to InDaily.

“The reforms Mark has called for have already been introduced in South Australia, which is one of the reasons the South Australian branch has enjoyed such strength and unity of purpose.”

However, Butler’s frontbench colleague Brendan O’Connor agreed Labor ought to look at boosting participation within the party, saying quite often office bearers were products of the factions.

O’Connor suggested it would be better for the ALP president not to be drawn from the frontbench, as Butler was.

“I think Mark is right to say we need to broaden our base and always look at ways to ensure we have the broadest participation of Labor supporters and Labor voters inside the party,” he told Sky News.

“I think there’s a bunch things we can do to open up the doors of the party to true participation and that would include making sure we share the office holders, so that executive don’t necessarily hold those positions.”

– with AAP