Former Tai Tokerau MP Hone Harawira says a blockade of the main routes into the Far North will go ahead today as planned despite the government declaring a level 4 Covid-19 alert from midnight tonight.

From noon today Harawira plans to have ''medical checkpoints'' set up on State Highway 1 at Whakapara, north of Whangārei, and on State Highway 12 at Waipoua.

Volunteers would check all vehicles heading north to turn back any tourists and ensure locals returning from overseas were complying with self-isolation rules.

''Internal checkpoints'' at other locations around the Far North would follow.

Harawira said much had happened since he first announced his plans — including the Prime Minister raising the Covid-19 alert to Level 4 — but it was ''too little too late''.

''Tai Tokerau will suffer from the Government allowing tens of thousands of tourists into the country before closing the border last week, with thousands of them roaming freely across the north without being tested, without self-isolating for 14 days, and without giving a damn for us,'' he said.

''We won't be standing down until we are convinced government is throwing the necessary resources into turning this threat around.''

Harawira said he had received hundreds of messages of thanks and offers of support, and he had spoken to police, Far North Mayor John Carter, iwi, and health authorities.

He had also talked to Te Whānau-ā-Apanui, the East Coast iwi which first moved to close off its rohe (tribal area).

On Monday night 20 of his Muriwhenua crew met Kaitaia police to outline how they would run checkpoints across the Far North. Last night he was due to meet the Ngāpuhi crew and Kerikeri police to cover off checkpoints in that area.

A flyer was being prepared to hand to people at checkpoints. It would explain the reasons behind the checkpoints, medical tips and advice for tourists and locals.

Former Kaitaia GP Lance O'Sullivan had agreed to act as the group's chief medical officer and was organising test kits, protective uniforms and caravans to support the checkpoints.

The free flow of food, medical supplies and emergency services would be ensured.

''We know that by setting up these medical checkpoints we are putting ourselves and our crews at risk of contracting the virus, but we have no choice. The country is moving to a war footing and we aim to ensure Tai Tokerau is ready to defend its territory and its people from Covid-19,'' Harawira said.

''We ask whānau to be safe, take care of your kaumatua and kuia, and find ways to keep your kids active and happy in these times of crisis.''