Twitter and Facebook users face $20,000 fines if they use their accounts to campaign for their favourite party or leader on election day.

Chief Electoral Officer Robert Peden said material posted on social media websites was covered by strict rules which prohibit electioneering on election days.

"People should be aware that if they tweeted on election day to influence how somebody votes they will be breaching the [Electoral] Act and the [Electoral] Commission will take action."

He said while people could leave websites with campaign material up on election day, they could not add further material or advertise the website.

"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."

The sites would be monitored on November 26, and people caught breaking the rules could face fines of $20,000, 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 Act prohibits electioneering of any kind on election day.

From midnight until 7pm, 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.

Yesterday, the Electoral Commission launched its enrolment campaign for the election by starting to mail out three million enrolment packs.

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

Meanwhile, online voting could become a reality by 2013 after Parliament's justice and electoral select committee recommended a trial at the local body elections that year.

The select committee included its recommendation in its report on the 2010 local body elections. It said the current postal system meant some voters did not get their papers in time while others were lost. Online voting could also increase turnout.

Select committee member National MP Simon Bridges said the main concern was the possibility of fraudulent behaviour.

"Nevertheless, we also appreciated that the internet is a potentially positive force given traditionally low voter turnouts at local body elections and its ability to make voting easier and more accessible."

Green MP Sue Kedgley also backed a trial, saying it was possible to have secure internet banking, so surely online voting could be managed.

The report coincided with the Electoral Commission's statement of intent in which it said it would look more closely at internet voting next year. It said it made voting more accessible, especially for those who lived a distance from polling booths. It said a phased introduction over several elections would be desirable to build public confidence.

Any move would be reliant on funding, and a move from paper to online voting was unlikely to save money in the medium term, it said.