Hundreds of Hungarian teachers have held a nationwide walkout and formed human chains around schools as part of a growing revolt against the government's tight grip on education.

Protests against Prime Minister Viktor Orban's sweeping centralisation of schools since 2012 began in November.

Rallies this month and last drew tens of thousands of teachers and sympathisers, in the biggest demonstrations in Hungary since 2014.

Organisers said teachers at more than 200 schools officially took part in the one-hour walk-out, and that individual teachers at many others also participated.

"This is the start," said Katalin Torley, a French teacher outside the Ferenc Kolcsey high school in Budapest where about 100 teachers joined a human chain.

"If there is no meaningful response by the government, we will gradually increase the pressure."

Official insults 'checked-shirt wearing' teachers

A list of 12 demands by organisers — the "I want to teach!" civil group — include reinstating schools' independence, cutting workloads for teachers and students and increasing state spending on education.

Mr Orban, whose shake-up of Hungary's state institutions has seen him labelled an autocrat by some, has pledged to make changes but insists that teachers join a government-led roundtable forum to discuss their concerns.

One protest organiser, Istvan Pukli, said more acts of civil disobedience would follow if the government does not sit down face-to-face with the teachers within two weeks.

Many of the demonstrators in the recent protests have worn checked shirts, which became a symbol of the protests after a former government official insulted "dishevelled checked-shirt wearing" teachers last month.

Teachers called Wednesday's action "civil disobedience" rather than a strike, as they say Hungary's current labour laws prevent any meaningful strike action.

"This is a different form of protest, it has never happened here before that an entire profession has stepped up in such a way," Ms Torley said.

Protesters walk in a 'living-chain' around the Kolcsey high school. ( AFP: Attila Kisbenedek )

AFP