Electronic stability control (ESC) will become compulsory for all new and used vehicles imported into New Zealand by 2020, the government has said.

The new law will be phased in over the next six years under a proposed timetable, Fairfax News reported.

Because the vast majority of new cars have ESC as standard, the proposal is to make it compulsory for all new vehicles from July 2015.

Local research shows ESC could reduce the risk of crashing from losing control by about 30% and the government predicts the rule would save more than 400 lives and prevent nearly 2,000 serious injuries over the next 20 years.

But New Zealand also imports vast quantities of used vehicles, mostly from Japan, so that source has been considered in the plans.

"To ensure maximum safety benefits from the new technology, without choking supply from the mostly Japanese used car market, I propose a phased implementation for imported used vehicles from 2016," a government minister said.

Because SUVs had the greatest roll-over risk due to their high centre of gravity, and had the biggest safety gains from ESC they would be the first used car category to come under the rule.

The rule would not apply to some imported specialist vehicles, such as vintage cars.

Public consultation opens on the draft rule in early March, Fairfax News said.