Anti-government protesters have walked out onto an Auckland motorway as police look on, causing traffic to back up for kilometres.

Several hundred people gathered at the Auckland Domain this morning, before leaving in a march led by Brian Tamaki.

They walked out onto the southern motorway at about 11.30am, as police blocked off all traffic heading south.

Southbound lanes on the motorway were closed as the protesters made their way from the Khyber Pass on-ramp to Market Road.

The leaders of the march reached the Market Road off-ramp and turned around to get back on the motorway in the other direction. All northbound lanes are now closed. The southbound lanes have reopened.

Anti-government protests have also been planned for other centres.

In Wellington, organisers told police a march was planned to travel between between Frank Kitts Park and the Railway Station, from 11am.

Police asked for drivers to avoid the area, if possible. They said officers would be present to ensure the safety of all.