The Solomon Islands Ministry of Education says the nationwide teachers strike is illegal.
More than 9 thousand public school teachers began an indefinite strike at midnight because of the government's failure to follow through on last year's agreement to fund pay rises and back-pay.
The Solomon Islands National Teachers Association says it will continue to strike until all arrears have been paid.
The acting permanent secretary of education, Aseri Yalangono, says the arrears will be paid as soon as the pay-roll has been cleaned up, which is expected to take until March.
He says the government took steps to deal with the issue within 14 days of SINTA's strike notice, but the union went ahead with strike action anyway.
Mr Yalangono says as a result, the matter has been referred to the Trade Dispute Panel.
"On Sunday, the Trade Dispute Panel issued a service message to teachers not to go on strike because then it would be illegal, so as it stands now the strike by SINTA as of midnight of Sunday can be interpreted as illegal."
Aseri Yalangono says the ministry is depending very much on the trade dispute panel to give the ruling that teachers must go back to work.