The BBC's Lisa Holland: "The Home Secretary echoed the Prime Minister's words"

Prime Minister Tony Blair says one of the measures under consideration is mandatory drug tests in police stations on people arrested for drug-related crimes.

Tony Blair: "We've got to change gear on this issue"

But civil rights group Liberty said the plan could fall foul of the European Convention on Human Rights.

Another proposal is a presumption against bail for people charged with a drug-related crime.

Speaking on BBC One's Breakfast With Frost programme, Mr Blair said the measures will form the central part of a new crime and justice bill, which will be outlined in the Queen's Speech in November.

He said the government had been working for several months on the initiatives, which he would unveil during his keynote speech at the Labour party conference on Tuesday.

But Liberty said the proposals were wrong in principle.

"The link between drugs and crime is problematic and needs to be broken but this is not the way to do it," said Liberty director John Wadham.

"Eroding rights won't crack crime and this approach misses the whole point, which is to stop people becoming problematic drug users in the first place.

The measures will anger civil liberties groups

"The government should drop the superficial macho rhetoric and establish a Royal Commission to undertake a radical review of drugs policy in this country."

But Home Secretary Jack Straw rejected the criticism, saying the offenders were "trampling over the civil liberties of 99% of the population who are the victims of their crimes".

He said people arrested also object to existing practices such as fingerprinting.

"It's always accepted that at the point of arrest, things happen which they may not wish to consent to," he said.

Mark Leech, Director of the National Association of Ex-offenders, known as Unlock, said the government must back up its reforms with resources to help people get off drugs.

'Terrifying statistics'

He said: "Putting in place legislation to deal with drug crime after the commission of offences is hopelessly ineffective unless it is coupled to the provision of resources to those who want to help themselves."

Both Mr Straw and Mr Blair said the country needs to "wake up" to the seriousness of the problem of drug-related crime.

Mr Blair said it was one of the "biggest social problems" facing the UK.

He quoted what he called the "terrifying statistic" that in some inner-city areas 50% of those arrested had drugs in their system.

Mr Straw said that there were about 120,000 serious drug users in the UK, about 60,000 of whom were arrested every year.

He said his "ambitious" target was to get drug-related crime down by 25% by 2005, and to halve it by 2008.

Mr Straw added that decriminalisation of cannabis was definitely not one of the "radical" proposals.