Thousands of free pill-testing kits will flood Sydney's music festivals this summer amid an ongoing row between the NSW government and health experts over the legalities of a professionally managed harm reduction trial.

With the summer festival calendar about to hit full swing and Premier Mike Baird holding firm on his government's threat to prosecute anyone associated with a pill-testing trial, Fairfax Media can reveal harm minimisation advocates have now vowed to carry out a "protest manoeuvre" involving "legal" do-it-yourself drug-testing kits.

"The MDMA content in an ecstasy tablet can vary widely and new synthetic drugs are constantly appearing on the market," Shane Rattenbury said. Credit:Viki Yemettas

The products enable people to test illegally purchased pills and identify the presence of a particular drug. But those behind the "Just One Life" campaign acknowledge the "basic" tests come with limitations and are unable to detect the presence of other potentially deadly cutting agents.

"This is definitely not our preferred option, it is our only available option," said Harm Reduction Australia president Gino Vumbaca​, who previously ran the Australian National Council on Drugs.