Cash-strapped Swaziland has let go 1,200 school teachers, leaving classrooms empty just one month into the school year, the main teachers' union said Friday.

Last year the tiny kingdom employed 3,000 teachers on one-year renewable contracts, with the promise of permanent jobs eventually.

Instead, 1,200 of the contracts have been dropped as the nation battles a crippling financial crisis, said Muzi Mahlanga, secretary general of the Swaziland National Union of Teachers.

"We met government and informed it of the appalling situation and gave them up to next week Wednesday to employ all the teachers currently left in the lurch," he said.

"Otherwise we will engage in a mass action that will ground the operations of schools," he said.

The teachers' union has been at the forefront of protests against King Mswati III, Africa's last absolute monarch, who is accused of keeping up his jet-set lifestyle while his impoverished nation suffers.

They led unprecedented protests against Mswati in April, with a series of regular protests through the rest of the year demanding broader political reforms to address the financial crisis.

Police fired teargas at university students on January 30, when they protested the government's failure to open the school for classes this year.

The government also has not made its payments for children who receive free primary education, or to its support for school going AIDS orphans.