An Auckland Council mayoral candidate's plan to introduce a "sinking lid" on Auckland Council staff is being rejected as impractical populism.

John Palino wants to make council services more efficient, introduce staff attrition and cut rates by 10 per cent.

But the Public Service Association said reducing the number of staff serving a growing population will lead to the deterioration of council services.

Union national secretary Glenn Barclay said putting extra pressure on existing staff will do more to undermine productivity than improve it.

"In the end [it will] be really disruptive within work places, which I don't think will impact positively on productivity or on efficiency."

He said an efficient council needs sufficient core staff and positive staff morale.

"All the candidates want the council to provide superb services but it simply can't be done without excellent staff delivering at the front and in the back office."