The organiser of Reading and Leeds, Melvin Benn, hopes drug testing will start soon at UK festivals but says the Home Office needs to issue a special licence for that to happen.
Pilots took place at last year's Secret Garden Party and Kendal Calling.
But festival promoters are waiting for the government's final approval to make sure they aren't breaking the law.
Melvin Benn says he's hopeful to have a licence in place by the time Reading and Leeds starts in August.
Speaking to Newsbeat at Community Festival in London Melvin, who also organises Latitude, V Festival and Wireless for Festival Republic, said: "The drugs testing is complicated because of the law [but] it's not complicated because of a desire to do it.
"This is such a detail - but it's an important detail.
"The people that are doing the drugs testing have to have a licence from the Home Office to be in possession of controlled drugs, otherwise they are in possession of illegal drugs.
"We haven't got that permission yet. When we get that permission, we can announce that it'll happen at Reading and Leeds, but until I get that permission I can't say it will."
The scheme has had its critics but Melvin Benn says festivals will be safer if drugs are tested.
"I'd say to the critics - open your eyes. Like it or not drugs are part of society.
"Anecdotally the evidence coming out of Holland is that, in the places that have this testing there hasn't been a death associated with MDMA since the testing came in. That to me is sufficient reason to go forward.
"Do I want people taking illegal drugs? Of course I don't. Am I condoning it? No of course I'm not. But testing is important."
When the scheme is confirmed, festival-goers will be able to take their drugs to a testing tent run by The Loop, an organisation which usually conducts forensic testing of drugs seized by police.
They'll then tell them what's in the drugs before destroying whatever was handed over.
Last year around 200 people tested their illegal drugs at the Secret Garden Party in Cambridgeshire.
"As far I was concerned until last Thursday, it was going to happen and then I got an email from the Home Office that said they hadn't got that licence, they can't do it.
"So now I'm waiting on the Home Office to give me the special licence.
"I think it will happen. There's a will for it to happen from West Yorkshire Police and Leeds City Council. Clearly we can't do it until we abide by the law."
You can find help and support on drink and drug use via these BBC Advice pages.