Labour's leadership candidates have already had to start reining in over-enthusiastic supporters in a bid to stop the contest becoming dirty.
Grant Robertson and David Cunliffe have asked unofficial Twitter accounts in support of them to close down, saying it could damage their campaigns.
One, called "Grant Robinson [sic] for Prime Minister" promised to stop tweeting after saying it had a direct message from Mr Robertson.
"As I don't want to do anything to harm his campaign, I'm out."
But a new unofficial account, called GrantforLabour, popped up soon after..
Yesterday, Mr Cunliffe also moved to try to shut down the Cunliffe for Leader account which had been sledging Mr Cunliffe's rivals - who it dubbed "beltway Grant and porno Shane" and tweeting in support of Mr Cunliffe.
Mr Cunliffe had denied it was one of his supporters
A Shane Jones supporter, called Run Shane Run, is also tweeting, but is largely well-mannered.
The party's general secretary Tim Barnett said there was a "clear expectation" contestants would try to keep their supporters under control, which would be included in a proposed code of conduct.
There was also a complaints process if supporters were offending others or doing damage to the party.
But there was little the party could do, other than ask for messages to be sent to the instigators by the person they were supporting. He said he had not received any formal complaints.
Questions have also been raised about the MPs' use of taxpayer money on the campaign trail.
As well as free domestic flights, there is a possibility the MPs could use some of their Parliamentary-funded advertising material, such as brochures, on the campaign. They can not use it for direct electioneering, but the rules are not as tight as in an election campaign.
All three said they intended to use Parliamentary travel during the two-week campaign, which includes a series of 12 meetings around New Zealand, starting on Saturday. Mr Robertson said that it fell within the rules and the salary package of MPs took into account a level of personal travel.
The three contenders had the first day back at Parliament yesterday after Mr Shearer's resignation last Thursday.
Each was given a question to ask of the Prime Minister or senior ministers in Parliament, and they have also begun setting our their stance on various policy issues.