The Campaign to Stop Killer Robots was officially launched in London on Tuesday (April 23) in an urgent move to pre-emptively ban the use of lethal robotic weapons that can kill without any human intervention.

A coalition of concerned groups is pushing for an international treaty to be written before the world "sleepwalks" towards a dangerous future where wars are fought by so-called killer robots.

In Parliament Square a "friendly" robot issued commands to passers-by in a stunt to mark the launch of the campaign, which includes groups like Human Rights Watch, the Nobel Women's Initiative and the International Committee for Robot Arms Control.

"Do we really want to delegate the right to take a human life to a machine? Do we?" Jody Williams, who won a Nobel peace prize for her campaign to ban landmines, said.

No-one knows exactly when such machines could be available for use in wars, but the Campaign predicts it will happen in the next two decades and stresses the need for the world to address the potential problems before it is too late to stop.

Over the past ten years the use of unmanned armed vehicles or drones has increased dramatically and has changed warfare, posing new humanitarian and legal challenges.

The Campaign fears that if left unchecked countries like the United States, Russia and China will be in an arms race to develop killer robots which would give full combat autonomy to machines.

"There has to be discussion about technology that will totally transform war. When my country wants to call it a bloodless battle I feel enraged, I feel righteous indignation at the twisting of words," said the American Williams.

Human Rights Watch says any development that is not able to be held accountable under international law will set back progress made in human rights, such as the Geneva Conventions.

"It seems to us extremely unlikely that you'd ever have machines that would ever be able to meet the basic requirements of the laws of war - international humanitarian law. We don't see how they are going to be able to distinguish properly between civilian and military targets," said Steve Goose, Executive Director of the Arms Division at Human Rights Watch.

The campaign predicts the biggest opposition will come from weapons producers who would stand to make a lot of money from new technologies and not national militaries, some of whom have already expressed concerns.

British members of parliament were handed a letter by the Campaign and were due to meet to discuss the issue later on Tuesday.

Presented by Adam Justice