ACT leader David Seymour is warning principals they're technically public servants - and must display political neutrality. 

The Associate Education Minister is hitting out at schools who've marked absences by students attending a national  hīkoi as 'justified'. 

Thousands marched through Auckland today on the pilgrimage to Parliament, protesting the Treaty Principles Bill. 

Seymour says parents can only urge schools to do the right thing. 

"Ultimately, it's up to communities to say to principals through their school boards - we don't like what you're doing and maybe it's time to get someone new."

LISTEN ABOVE

• Hīkoi protest: Thousands cross Harbour Bridge, head for key Auckland sites
• 'Deliberate disruption': Auckland motorists fume ahead of rush hour hīkoi protest over harbour bridge
• David Seymour says parents could face prosecution for kids' truancy
• Ministry of Education now producing daily school attendance data
• 'Unacceptable': Seymour tells schools to mark climate protest students absent