There is dispute from within Canterbury DHB over whether patient services will be impacted amid massive cost-cutting measures.

The Government's asked the DHB to reduce its $180 million deficit - the largest in the country - by almost $57 million this year.

It has also seen seven senior executives resign and hundreds of hospital staff protest on the streets.

CEO David Meates - who'll be stepping down next month - says it will impact on service delivery, but this will be minimised where possible.

But Crown Monitor Lester Levy told Heather du Plessis-Allan no patient services will be lost.

"The cost savings cannot cut services or impact equity because that it is a bottom line from both the Ministry and the board."

He says the DHB was told in 2015 it needed to stop overspending.

"They received a letter from Bill English in the previous government seeking for them to improve their financial performance when their defecit was just under $18 million.

"In five years, it has increased by 10 times."