The Auckland Harbour Bridge is set to again be the centre of anti-Government protest action with a convoy of tractors planning to roll across it this morning.

Around two dozen large tractors have commandeered the left lane of the Southern Motorway and are nearing the bridge in the latest Groundswell NZ protest takes to city roads.

Waka Kotahi NZTA said its Auckland Traffic Operations Centre is monitoring all traffic.

"We will provide updates on any disruptions or congestion via our social media channels.

"We advise people to check the latest conditions before travelling in the city, and consider using the Western Ring Route as an alternative if travel over the bridge is disrupted," said senior media manager Andy Knackstedt.

While the protest route is unclear the protesters left South Auckland and headed up the Southern Motorway to the Auckland Harbour Bridge before returning through downtown Auckland.

An AT spokesperson said the convoy was travelling in the left lane of the motorway without causing disruption.

The control room team and police liaison officer were managing the situation.

Around two dozen tractors have turned up to take part in the demonstration that will cover at least 80km.

Groundswell NZ said today's demonstration was to launch its latest non-compliance campaign.

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"Our campaign to SAY NO is a short-term necessity, until the Government puts in place workable regulations that achieve real environmental outcomes and respect the privacy and property rights of those they affect," said Groundswell NZ's Bryce McKenzie.

He said farmers would be driving tractors over the Auckland Harbour Bridge in protest of the unworkable regulations and breaches of privacy and property rights.

"Food producers will no longer jump through the Government's hoops and provide information that is used to advance a policy agenda hostile to farmers, property owners and rural communities.

"The Government's continued assault on food producers has made today's awareness-raising action necessary," said McKenzie.

Auckland mayor Phil Goff today urged police to move swiftly should the demonstration break the law.

"While people have the right to peaceful protest, police should take action against any unlawful behaviour that seriously and unnecessarily disrupts people going about their day-to-day lives."

It is the latest in a string of anti-Government protests that have targeted the bridge.

Last month, police escorted a Freedoms and Rights Coalition convoy over the bridge as it made its way south to a rally in Wellington.

In May people jumped out of cars during a protest over the bridge, with 11 arrested.

Earlier in the year around 2000 anti-mandate protesters linked to the Brian Tamaki-led Freedoms and Rights Coalition walked across the bridge, closing it to traffic for 90 minutes on a busy Saturday morning.

A woman driving one of the many tractors that converged in Auckland's CBD last November. Photo / Alex Burton

The Groundswell movement is a rural protest faction formed in 2020 opposing regulations on the sector. It has used convoys of tractors and farm vehicles in cities to draw attention to its cause.

Last November during the Delta outbreak hundreds of tractors, 4WDs, utes and other vehicles rolled into Auckland's CBD and other town centres as part of a nationwide Groundswell protest.