The Christmas and millennium holiday will see an "explosion" in the use and availability of club drugs including ecstasy and amphetamines, the National Criminal Intelligence Service has warned.

The agency says that intelligence from both the UK and the continent points to more drugs being imported - and more drugs being made in laboratories in the UK.

Its officers have reported larger movements of the chemicals required to make drugs such as LSD and GHB.

1n 1998-1999, eight drug laboratories in the UK were uncovered and the manufacturers arrested.

And NCIS is warning that organised criminals will attempt to flood the UK with synthetic and illegal drugs over the festive period.

The head of the NCIS drugs section, Nick Wilson, said he was particularly concerned that "young, impressionable, party-goers" will feel under great pressure to have a good time this new year, and might try drugs for the first time.

He added: "NCIS is aware of the great diversification of the drugs market in recent years, and the millennium offers what may be viewed as the perfect opportunity for widening that market further."

The government's drugs czar Keith Helliwell said: "Some of our children are putting their lives at risk over the New Year period. I would really urge them not to participate in taking these substances."

But drugs organisations say they doubt the increase of drugs available will be any greater than during any other festive period.

Mike Goodman director of the drugs charity Release, said that every Christmas and New Year saw an increase in the availability of ecstasy, and its many variants, and amphetamines.

He said that cocaine consumption had also been on the increase for some time, and that it was likely to increase further as people celebrated the millennium.

He said: "It's seen as a champagne drug, and people are going to be drinking a lot of champagne this Christmas.

"They're also going to be smoking a lot of cannabis. But the biggest danger is alcohol, and just as people should be very careful about the drugs they are taking, they should also be extremely careful about how they drink. They should make sure they don't set out to overdo it."

But Mr Wilson said that this year's demand for drugs is "unprecedented".

He added: "The relentless criminal pursuit at any human cost has created a highly dangerous environment.

"These drugs are not only illegal but can cause irreparable damage, especially at a time when over-indulgence is not only the norm, but actively encouraged.