Some 21 Victorians have died waiting for an ambulance over the past six months, a budget estimates hearing has been told.

Failures in the triple zero system have been blamed for 18 of those deaths, with three attributed to paramedics not getting to patients on time, Ambulance Victoria’s acting chief executive Libby Murphy said on Friday.

Excessive demand for ambulances resulted in four ‘code red’ events, while a ‘code orange’ has been called 51 times, Ms Murphy revealed.

Response times are also struggling with paramedics attending the most serious cases within the recommended 15 minutes only 60 per cent of the time.

Opposition MP James Newbury accused Health Minister Martin Foley of having blood on his hands during the hearing, calling on him to apologise to families.

“We have 21 deaths, this isn’t a joke,” Mr Newbury yelled.

“Those families deserve the word sorry, minister, and here is your opportunity.”

Mr Foley said he had apologised and that any death was a tragedy.

The hearing follows Thursday’s announcement by the state government of a major overhaul of the Emergency Services Telecommunications Authority.

A report into ESTA by former Victoria Police chief commissioner Graham Ashton found “continued and systematic underperformance” within the service.

Mr Ashton made 20 recommendations, including moving ESTA into the Department of Justice and Community Safety, renaming it Triple Zero Victoria and disbanding the current board.

All have been accepted in principle by the government.

Earlier on Friday, Mr Foley dodged questions about when he first received the ESTA report.

The health minister said his department had a number of opportunities to respond to the review, but would not say when it first landed on his desk.

– AAP