The Baird government has pledged $100 million to protect the state's threatened plants and animals if it wins office at next week's state election.

"We can provide the greatest opportunity to halt the loss of our threatened plants and animals," said environment minister Rob Stokes, who appeared at Taronga Zoo to announce the funding on Friday.

Mr Stokes styled the funding as "the very biggest commitment ever in Australian political history".

The funding would be spent over four years and, the government says, would be used to fund programs to protect all 970 native species  from pests with measures such as fencing and improved soil quality.

The government says this is a significant expansion on the 70 species that had protection programs.

Mr Stokes said the government's strategy is to remove species from the list of endangered animals. It argues the list has expanded for too long and according to political decisions.

Supporters of this "targeted" approach note that not a single animal has been removed from the threatened species list since it was created in 1995.

The government's "Saving our Species" approach instead divides animals into streams according to the likelihood they can be saved successfully and the cost and benefit to society of protection.

When the government first announced this new approach more than a year ago, it committed only $5 million in funding, or only enough for measures to protect about 70 of the state's 970 species.

Critics said that approach left a large proportion of the state's protected species to fend for themselves and that the government was prioritising "iconic" species such as the koala, at the expense of those such as the Hastings River mouse.

They will still receive special attention under the law. But Mr Stokes said Friday's announcement represented a "tenfold" increase in funding for species protection, that will expand work to all 970 native species, including both "iconic and less-well-known threatened animals".

"With this funding today we'll be able to complete that work [we started in 2013]," he said. "We want to identify recovery plans for each and every species."

Environment groups welcomed the announcement on Friday but expressed caution about other threats to species.

Jeff Angel, from the Total Environment Centre, described the announcement as an "impressive contribution". But Mr Angel warned that habitat loss remained the major threat to wildlife loss, and the government needed to retain powers to stop it.