Labour candidate Michael Wood has comfortably won the Mt Roskill by-election, with more than double the votes of the next contender.

Photo: RNZ / Sarah Robson

With 100 percent of votes counted, Mr Wood has 11,170 votes, more than double that of the National Party candidate Parmjeet Parmar who has 4652 votes, a lead of 6518 votes.

The Peoples Party leader Roshan Nauhria came third with 709 votes.

While speaking to her supporters gathered at Frolic Cafe in Royal Oak, Ms Parmar said the loss was disappointing, but she had a good campaign.

Ms Parmar said she intended to stand again as National's candidate in the next election.

National's campaign chair Steven Joyce said despite the loss, Ms Parmar was a good candidate.

Parmjeet Parmar thanks supporters. Says she will still champion Mt Roskill despite loss. @rnz_news pic.twitter.com/8wuJYzsdUW — Mei Heron (@meiheron) December 3, 2016

The turnout in the by-election was considerably down on the count in the seat in the 2014 general election.

In 2014 more than 33,000 people voted for a local MP, but slightly more than half that number cast a vote in the by-election.

Mr Wood's margin was convincing, but it was down on Phil Goff's margin of more than 8000 votes.

The by-election was triggered by Mr Goff leaving the seat he's held for decades to become Auckland's new mayor.

Mr Goff made a brief appearance at Mr Wood's election night function.

He picked Mr Wood to win, although he expected his 8000-vote majority at the last election would be reduced.

Auckland mayor Phil Goff has made a brief appearance at Michael Wood's election night function @rnz_news pic.twitter.com/SzjWu3eiDp — Sarah Robson (@rarahsobson) December 3, 2016

Mr Goff had endorsed Mr Wood during the by-election campaign.

Although there are no final figures on turnout available yet, advance voting at the by-election was well down on the 2014 election.