Senior cabinet ministers have been put in charge of fixing the error-ridden teacher pay system Novopay.
It has been failing since it was rolled out in August and Associate Education Minister Craig Foss hasn't been able to do much about it.
Prime Minister John Key has decided the government's "Mr Fixit" Steven Joyce will be able to find out what's wrong with Novopay, working with Finance Minister Bill English.
"I suspect the problems are deeply embedded," Mr Key said on Tuesday.
"We need senior ministers to drill down into it. Fixing the problems are a priority."
Mr Key says Mr Joyce is a tough and meticulous minister.
"If I was running Novopay I'd consider myself on notice," he said.
Novopay is supplied by Australian company Talent2, which has apologised for thousands of errors and has promised to fix the system.
It consistently failed to meet deadlines set by Mr Foss, and the government has previously said it is looking at penalty clauses in the contract.
As Mr Key was making the announcement, Labour released the latest list of Novopay's faults.
Associate education spokesman Chris Hipkins says Mr Foss has at last supplied him with details showing 7899 teachers were either underpaid or not paid at all.
Another 581 were paid on behalf of schools they weren't working at and the Ministry of Education has had to give schools advances totalling $560,000 to cover mistakes.
Mr Hipkins says Novopay abandoned 15,000 calls to its help line and teachers who did get through had to wait more than an hour.
"The botched system is expected to cost taxpayers $189.5 million over 10 years," he said.
"For that sort of coin, Kiwis expect excellence."