The Scottish wildcat is under threat from interbreeding - hybridisation -with feral and domestic cats.
The Scottish Wildcat Association (SWA) estimates there could be just 35 left in the wild.
The Scottish Government's initiative, to be led by Scottish Natural Heritage (SNH), aims to reverse the decline within six years by reducing the chances of cross breeding with domestic cats and lowering the risk to wildcats from feline diseases.
But Steve Piper, the founder and former chairman of the SWA, formerly a member of the SNH Wildcat Action Plan Group said the SNH's definition of what constitutes the animal is too relaxed. He added: "In short, anything that looks roughly two-thirds wildcat will be classified as a wildcat".
He said this means the scheme would lead to the protection of hybridised cats instead of protecting the few remaining animals in the wild that carry wildcat DNA exclusively.
Setting the threshold so low would mean that "the pure and near-pure wildcats that are still out there will be condemned to hybridise down to the lowest common denominator". He said the launch was the day it was forced into extinction.
He said: "This is a shameful effort from the Government after an entire year of consultation and a truly tragic day for the Scottish wildcat, which deserves so much better."
An SNH spokesman said: "We are disappointed that Steve has felt the need to raise this now when other partners are seeking to work together constructively.
"We have recently commissioned further research to establish current levels of hybridisation in key populations. If we find cats which are of good ancestry that is fantastic, but we need to be pragmatic."
l The great-crested newt and natterjack toad have been boosted in their survival fight by a £422,000 grant from the Heritage Lottery Fund for the Scottish Dragon Finder conservation project.