Sam Dastyari’s primary trial for Sydney lord mayor has become mired in branch-stacking allegations and a secret three-way preference deal just one day after polls opened.

Late yesterday, Crikey obtained a leaked email sent by Chinatown candidate Jonathan Yee to Kings Cross branch president Phillip Boulton detailing a stitch-up that will see himself, legal type Damian Spruce and refugee agitator Linda Scott swap preferences to decide who will lose to independent Clover Moore in September.

Yee coolly explains his rationale: “We are doing a triangular deal whereby I give Linda the number two on my ticket and Linda gives Damian the number two on her ticket. In turn, Damian gives me number two. Number three goes in the opposite direction.”

He then bizarrely admits he had failed to preference his most preferred candidate. Murphy was the “most worthy candidate … but my deal with Linda and Damian has been confirmed. I apologise if I have disappointed you.”

Yee has been accused by rival Cassandra Wilkinson of vigorously recruiting of his close associates at the $5 concessional membership rate. In his email, Boulton alleges the restaurateur had recruited “over 100” members in the past few weeks to buttress his support.

Wilkinson, the founder of FBi Radio and another candidate, NSW Civil Liberties chief Cameron “son of Lionel” Murphy, say the machinations are an echo of the dubious scheming Labor was trying to bury by embarking on the US-style primary in the first place.

Murphy, who is not allocating preferences, told Crikey the revelations were “disappointing” .

“This process is meant to let the community decide who the ALP candidate is … this is the sort of conduct we’re trying to get away from based on mathematical deals rather than merit,” he said. “I entered the race because it was a community preselection … it’s important that this process succeeds, it’s about taking power away from faceless people in back rooms.”

Wilkinson, who is preferencing Murphy, said in a written statement this afternoon she was “sorry to see the same old politics as usual from some candidates. Cameron and I have tried to break away from that.

“If they had courage of convictions they would have put me last not Cameron. My policies are much less like theirs than his but they shafted him … It’s putting him last that gives them away.”

Online polling opened yesterday for the historic vote, in which a 50% community competent (excluding members of other political parties) will be combined with a 50% vote of ALP members. How-to-vote cards and candidate statements are currently wending their way to Sydney’s 90,000 residents.

The preference deal will boost Scott’s standing in the membership component, which she is expected to poll well in. On Twitter Scott said she had alerted the ALP to the branch stacking allegations and was awaiting a response.

Also on Twitter, Dastyari denied that HTVs were relevant because the poll was online. However, in a subsequent Tweet, he admitted voters could be sent “suggestions”.

Yee told Crikey yesterday he had recently recruited some new members, explaining that only two of the 100 were snared at the $5 “Bob Hawke” rate, with the rest signed up at the appropriate concession rate.

When asked whether the members were recruited to increase his chances, Yee said the following: “How can I answer that? At the start of the process, head office asked us to recruit new members to help us strengthen our own support.”

Asked why he didn’t preference Murphy when he preferred him as a candidate Yee said that Scott had approached him early on with the deal to lock-in support among less popular candidates: “you want the weaker candidates supporting you so you can ensure you have that person’s vote when that person drops off.”

Last night, in an eleventh-hour twist, a Yee how-to-vote card came to light which failed to direct preferences, in apparent contradiction of the terms of the deal. The open ticket instead instructs voters to number boxes 2-5 however they wish.

The nascent experiment with grassroots democracy is the first to be held following the Prime Minister’s strong urgings last year that state Labor branches conduct primaries and report back to National Conference with the results.