Government scientists are being sent to the V Festival to analyse samples of so-called legal highs amid renewed warnings against taking the party drugs.
The Home Office is launching a national campaign highlighting the risks of legal highs including laughing gas, which was more widely used than powdered cocaine and ecstasy last year.
They are aiming to gather information about which new substances are available in the UK, and the latest Home Office annual report on the trends is due to be published today.
More top news
Man's best friend really does understand some of what we are saying, scientists are suggesting.
Selena Gomez said she was taking time out to deal with panic attacks and depression thought to be a side effect of her lupus disease.
Temperatures will be highest in the southeast, reaching a high of 24 Celsius (75F) here.