Twitter users will be in line for $20,000 fines if they are caught campaigning on election day.

The Electoral Act prohibits electioneering of any kind on election day, making it illegal to distribute or broadcast any statement likely to influence a voter's decision.

From midnight until 7pm on election day, election signs must be taken down or covered up, vehicles advertising parties or candidates must be out of public view, and no campaign material can be distributed.

Labour MP Chris Hipkins yesterday questioned how social media would be affected by the rules come the November 26 election.

"Technically, an ordinary member of the public tweeting on the day 'I've just gone and voted to get rid of that idiot xxx' or 'It's election day. Get out there and vote for our future and vote xxx' is breaking the law," Mr Hipkins wrote on Labour's Red Alert website.

"What about if someone comments on an MP or candidate's Facebook page with something like 'Good luck, hope everyone gets out there and votes for you'?"

Chief Electoral Officer Robert Peden said material posted on social media websites, including Facebook and Twitter, was covered by the rules.

"People should be aware that if they tweeted on election day to influence how somebody votes they will be breaching the Act and the commission will take action," Mr Peden told NZPA.

"For a long time, the law has allowed for campaign-free election days, and my sense is that New Zealanders like it that way and so it's not really in people's interest to do things like tweet and breach the rules."

While people are allowed to leave websites with campaign material up on election day, they may not add further material or advertise the website.

The sites would be monitored on November 26, and that people caught breaking the rules could face a $20,000 fine, Mr Peden said.

"It's the sort of thing that we will hear about if someone's doing it. We'll receive complaints."

The Electoral Commission today launched its enrolment campaign for the election, with three million enrolment packs to be sent out by next Wednesday.

The packs also contain information about the referendum on MMP, which will coincide with the election.