ALP leadership aspirant Anthony Albanese will do what none of his predecessors have had to tonight, when he launches his campaign to be voted in as Labor leader. For the first time, he (and rival Bill Shorten) will have to appeal directly to party members, who will vote on who should be leader.

It has the feel of an experiment in Australia, but similar systems have been operating for some time overseas. Crikey decided to look into how similar systems work (or don’t work) in the UK and New Zealand.

The New Zealand Labour Party has just chosen its new leader under rules similar to those brought in by Kevin Rudd. David Cunliffe beat two other contenders, Grant Robertson and Shane Jones, in the race to take the opposition to the 2014 election. The NZ rules give rank-and-file members 40% of the vote, the caucus 40%, and affiliated unions 20%. This is a slightly different balance to the ALP, whose ballot will be divided equally between the caucus and rank-and-file, while trade unions will not have a direct say.

Cunliffe said that critics “said that we couldn’t run this first primary in New Zealand history without tearing ourselves apart, and they were wrong”. Grant Robertson said he thought the process had been “tremendous” for the Labour Party, which had been “re-energised and revitalised”.

But some worry this very public way of doing things will undermine party unity. Cunliffe received the first preference support of only 11 of the 34-strong caucus — less than one-third — while rival Robertson won the backing of 16 MPs. Second preferences still favoured Robertson 18-16. It was only winning 60% of the membership and 71% of the union vote that got Cunliffe over the line.

There could be a similar split between the party room and the rank-and-file in ALP elections. This could feed into the narrative of the opposition divided — but equally could give greater democratic legitimacy to the victor and party.

There appear to be similarities over the Left-Right dynamic between NZ and here. Across the Tasman, while MPs showed more support for the candidates on the Right, the party base helped elect “the only senior MP articulating the view of the Labour Left”. Left-aligned Albo’s predicted grassroots popularity may lead to a similar upset in the factional balance, which has until now favoured those on the Right.

Recent reforms in Australia and NZ are based on British Labour. The UK rules, created in the early 1980s, originally divided the vote 40-30-30, giving unions the most votes. This was ostensibly because the union dues paid to Labour represented many times more workers than the party membership.

As union membership fell, Labour amended its voting procedures so that decisions are now divided equally between the membership, parliamentary party, and affiliated organisations.

Union participation in the British ballot has been controversial, however. Some see Ed Miliband’s selection as being overly influenced by the unions. Brother David Miliband won a higher proportion of the membership and MP vote, but a strong “affiliated organisation” showing for Ed resulted in him taking the leadership. To some, the primaries did not seem particularly open and democratic.

Rudd, never a fan of the unions, decided to leave them out of the process altogether. In the words of Labor strategist Bruce Hawker: “There is no doubt that by moving power away from factions and some affiliated unions to the rank-and-file there will be much greater influence exerted by ordinary members.”

Hawker says the ALP has lagged behind similar parties in the United States, UK, Canada, France and Italy, where open primaries have been key to re-energising supporters. In an age where media increasingly focus on personality politics, letting members decide should be a good test of the prospective leaders’ ability to win over the public. Though those in positions of factional control may not like it, the reforms should increase the democratic legitimacy of the ALP.

Under the ALP’s new rules, the ballot will be conducted by postal vote, to be mailed to members after nominations close on Friday. The membership will vote first, after which MPs will cast their ballots. The results of the popular vote will not be known to the caucus when they vote.

Anyone who was a financial member of the ALP on election day can vote. It had previously been expected that only members who had been paid-up for two years would participate, but the party decided to widen eligibility,

Labor national president Jenny McAllister says “there is absolutely a sense that this represents a really important part of the Labor renewal process … that we have got all of these people involved and we want to say to them, you count. Your vote’s going to count. We’re grateful for your support and you will be part of determining our future.”