Winston Peters, leader of the right-wing populist New Zealand First Party, won a landslide victory in Saturday’s by-election in the northern seat of Northland, which was held by the ruling National Party for more than half a century.

The by-election was prompted by the resignation of National MP Mike Sabin, who is being investigated by police for undisclosed reasons. Sabin was elected in last September’s general election with a majority of 9,000. In a major turnaround, Peters won the by-election with 15,359 votes, compared to National candidate Mark Osborne’s 11,347.

The result means the National government now holds only 59 out of 121 seats in parliament, and will have to rely more heavily on its three support parties: the Maori Party, the far-right ACT Party and United Future, which between them hold four seats. NZ First will have an extra MP, increasing its numbers from 11 to 12.

The result points to a significant shift against Prime Minister John Key’s government, which was initially elected six years ago and has presided over increasing social inequality, attacks on democratic rights and militarism. The New Zealand Herald stated that Peters’ “stunning” victory could be “the turning of the tide” against the government. A Dominion Post editorial yesterday said it was a “humiliating blow.”

Northland epitomises the social catastrophe in New Zealand. It has the lowest median income in the country ($23,400 according to the 2013 census) and some of the most run-down infrastructure. There is also widespread opposition to the Key government’s plans to send troops to join the US-led war in Iraq—which was not announced before last year’s election. In addition, the lead-up to the by-election saw further revelations of the Government Communications Security Bureau’s mass surveillance throughout the Asia Pacific region.

Peters’ victory is being celebrated by the opposition Labour Party, its allies the Greens and the Maori nationalist Mana Party, and by “liberal” commentators in the media. These parties boosted Peters’ prospects by promoting him as a “lesser evil” to National. Labour leader Andrew Little basically instructed Labour supporters to vote for Peters, while the Greens did not stand a candidate.

The opposition’s embrace of NZ First reveals the profound shift to the right by the so-called “left” parties. They have united to channel mounting anti-government sentiment in the most reactionary direction.

NZ First is a viciously anti-Asian party. Its members regularly rant against Chinese and Indian immigrants, scapegoating them for every aspect of the country’s social crisis, including low wages, unemployment and the lack of affordable housing. The party has also demonised Muslims as potential terrorists, and pushes for increased military spending and more hard-line “law and order” policies.

Labour, the Greens and Mana have all adapted themselves to NZ First and joined in its anti-Chinese campaigns over the past three years. Last year, Labour and the Greens promised, if elected, to form a coalition government with NZ First. This alignment also feeds into Washington’s push to integrate New Zealand into its strategic “pivot to Asia,” aimed at militarily encircling China.

Much of the corporate media swung behind NZ First, with a Dominion Post editorial stating that “Peters will make a much better local MP than an unknown National hack.” TV3 and RadioLIVE broadcaster Duncan Garner backed Peters, labelling his opponent Osborne “a numpty.”

Pro-Labour columnist Chris Trotter hailed Peters’ supposed “gravitas and honesty” in the campaign. The Daily Blog, which is funded by five trade unions, campaigned vigorously for Peters, featuring regular columns by NZ First Youth leader Curwen Rolinson.

Revealing his utter contempt for the working class, Daily Blog editor Martyn Bradbury justified his support for NZ First by claiming that the party’s “garden variety racism” would appeal to Northland voters, whom he slandered as “rednecks.”

Green Party co-leader Metiria Turei congratulated Peters on his “historic” victory. She stated that “his election is a clear message” that the government is “out of touch” with Northland residents.

The Mana Party’s candidate in Northland, Rueben Taipari Porter, wrote in Mana News that he was “proud to have been a part of [the] historical change.” He absurdly declared that the installation of Peters would mark “perhaps the beginnings of a new political strategy to bring the power back to the people.”

Porter received 55 votes in the by-election—fewer than the ultra-right ACT (66 votes) and the Aotearoa Legalise Cannabis Party (85 votes) candidates. This result was the outcome of Mana’s “political strategy” to assist the NZ First leader.

The pseudo-left groups Fightback, Socialist Aotearoa and the International Socialist Organisation (ISO) are complicit in the promotion of NZ First. All these middle class outfits campaigned for Mana and its ally, the openly pro-business Internet Party, in last September’s election. They fraudulently portray Mana as “anti-capitalist,” “pro-poor” and anti-racist.

In reality, Mana is a bourgeois party. Like NZ First, it has campaigned against Chinese investment and called for restrictions on foreigners buying houses and discrimination against migrant workers.

The pseudo-lefts have not criticised Mana for embracing NZ First. These groups also work within the Unite trade union, which invited Peters to speak at its November conference, where he blamed poor working conditions on immigration.

In a post by-election attempt to cover its political tracks, an article by the ISO pointed to Peters’ “anti-Asian racism” and said his victory was “no win for workers.” It noted that “some on the left and in the unions have been excited by the prospect of his win” and said this was because of Peters’ nationalist opposition to the US-led Trans-Pacific Partnership trade talks. The article was silent, however, on the promotion of NZ First by Mana and Unite.

The main thrust of the ISO article was to offer friendly advice to the Labour Party, describing its endorsement of Peters as “a mistake.” It stated that Labour “should have fought for Northland with radical policies.” Following Labour’s landslide defeat in last year’s election, the ISO is seeking to revive illusions that the party can be pressured to endorse “radical” changes.

In reality, as masses of working people recognise, Labour is a party of big business and militarism just like National. It abandoned any reformist policies three decades ago and began a wave of privatisations and other attacks on social services and living standards, which continues today under the National government.

The pseudo-lefts, through their support for Labour and Mana—and, indirectly, NZ First—aim to improve their own positions within the political establishment and to prevent the emergence of an independent movement of the working class against the capitalist system.