Families who have lost loved ones to drugs are calling on the prime minister to meet with them to discuss alternatives to current government policy.

Family members of people who have died or gone to jail due to drugs went to Downing Street today demanding reform of Britain's drug laws or a royal commission to investigate alternatives.

The visit came ahead of a Lords debate on the new psychoactive substances bill.

The controversial bill would outlaw almost all substances which have an effect on people's thoughts or emotions, in a marked escalation of the war on drugs.

It comes as much of the world experiments with a more liberal approach to drug control, including several US states, which are either decriminalising or legalising cannabis for recreational use.

"Our vicious and stupid drug laws don't stop young people from taking drugs," a spokesperson for today's Anyone's Child campaign said.

"But putting dangerous criminals in charge has devastating results for them and their families.

"In 2002 David Cameron called for a debate on legal regulation. Since then, there have been over 26,000 drug deaths in the UK - compared with 453 UK soldiers in Afghanistan.

"Enough is enough. He should immediately commission an independent review of our drug laws. The government knows the evidence proves that legally regulating drugs would help protect all our families."

Among the families telling their story in the organisation's first event is mother Anne-Marie, whose 15-year-old daughter Martha died of an accidental ecstasy overdose.

Elsewhere couple Mike and Hope described how their son served a prison sentence intended for dealers because he picked up drugs for himself and his university friends at the same time.

A sister called Katrina also told the story of how her brother was killed after being dragged into "the edge of society" in a bid to secure the heroin he was addicted to.

Anne-Marie: "My only child might still be alive if ecstasy was regulated"

"On 20th July, 2013, I received the phone call that no parent wants to get. The voice said that my 15-year-old daughter was gravely ill and they were trying to save her life. On that beautiful, sunny Saturday morning, Martha had swallowed half a gram of MDMA powder (more widely known as ecstasy) that turned out to be 91% pure. Within two hours of taking it, my daughter died of an accidental ecstasy overdose. She was my only child. 'Martha wanted to get high, she didn't want to die'. All parents would prefer one of those options to the other. And while no-one wants drugs being sold to children, if Martha had got hold of legally regulated drugs meant for adults, labelled with health warnings and dosage instructions, she would not have gone on to take five to ten times the safe dose. "When I hear that a young person has died and yet another family has joined the bereaved parents’ club, I feel helpless as I wonder how many more need to die before someone in government will actually do something about it? As I stand by my child's grave, what more evidence do I need that things must change? Isn't this loss of precious lives an indicator of a law that is past its sell-by date and in need of urgent reform? A good start would be to conduct the very first proper review of our drug laws in over 40 years and to consider alternative approaches. But the people in power turn away from it."

Mick and Hope: "Our son's life has been blighted by the drug laws"

"Our son James was in his second year at Manchester University when it happened. We'd just come back from the local supermarket, when the phone rang, and our lives were changed forever. James was at a police station on a drugs charge. Neither of us knew much about illegal drugs, and I shudder now to think how ignorant we were. "James had taken his turn to get cannabis and ecstasy for his household of adult university friends. He made no profit but the drugs were cheaper if you got enough to last the term. They were in a bowl in the communal sitting room from which they all helped themselves. But James had told the truth about being the one to get them that time. Ecstasy is a class A drug and the law does not differentiate between a feckless student and a drug dealer. Prison is the only outcome for the intent to supply a Class A drug. When he got to Strangeways his cellmate was a Moss Side gangster who had chopped off the fingers of one of his victims, and stabbed a man in the heart. "After he came out of prison having served 15 months of his two-and-half year sentence he went back to study. But James's life has been blighted. No-one could avoid being scarred by what he has experienced. And he still has a criminal record that has affected his career prospects. Despite his masters degree, he now sells carvings by the roadside. When something so unjust happens, if it doesn't destroy you, you want to do something about it. So our family began to fight for an end to these cruel and draconian laws so others won't be afflicted in the same way. But for now, what happened to us could happen to you."

Katrina: "My brother was marginalised and then murdered because of the drug war"