Chief District Court Judge Jan-Marie Doogue has made a strong plea privately to Attorney-General Chris Finlayson to address the falling number of judges, a confidential letter shows.

The letter from her to Mr Finlayson was leaked to Labour justice spokesman Charles Chauvel - another embarrassing leak for the Government after a series of leaks from the Ministry of FOreign Affairs and Trade.

The letter dated May 2 was copied to all 147 district court judges and Mr Chauvel said he was sent four copies of it - none from Judge Doogue.

It expresses concern at Ministry of Justice advice that 23 district court judges would be surplus to requirement in upcoming years because of the impact of policing excellence and a drop in crime.

She pleads a case for Mr Finlayson to at least extend Acting Warrants for retired judges willing to continue "in the face of an inability to secure new judges to replace those who have retired."

She projected retirements of permanent and acting judges for the next 10 years and said the total attrition rate for permanent judges over 10 years was 36 per cent and for acting warranted judges, 78 per cent.

"The large number of permanent judges retiring from 2018 onwards is a significant risk for district courts."

She was seeking the immediate extension of an acting warrant, a new acting warrant and the appointment of two new judges to Auckland to support the work work of judges particularly in South Auckland.

Under questioning in Parliament yesterday by Mr Chauvel, Mr Finlayson said he had doubts about the number of 23 judges being surplus as stated by officials.

"That figure has been mentioned. For myself, I have doubts as to whether it is a correct figure. As to the number of judges it will always depend on the circumstances."

He said the advice had been no more than a "preliminary draft" and more work was being done on it.

He said it was not in the public interest to comment on any discussion he had met with the judiciary.

Mr Chauvel asked for an assurance that neither he nor his ministerial colleagues had admonished any judge for speaking about Government policy proposals or for making submissions to select committees.

Mr Finlayson said he did not know what he was referring to.

Mr Chauvel told the Herald later that some of judges believed the cutback in the numbers was a response to criticisms judges had made publicly to criminal law reform.

By Audrey Young Email Audrey