The future is coming at Croydon fast. It might not look like Britain's cutting edge but North End, a pedestrianised high street lined with the usual mix of pawn shops, fast-food outlets and branded clothing stores, is expected to be one of two roads to host the UK's first fixed facial recognition cameras. Digital photographs of passersby will be silently taken and processed to extract the measurements of facial features, known as biometric data. They will be immediately compared by artificial intelligence to images on a watchlist. Alerts can lead to arrests.

Police believe live facial recognition cameras may become "commonplace" in England and Wales, according to internal documents, with the number of faces scanned having doubled to nearly 5m in the last year. A joint investigation by the Guardian and Liberty Investigates highlights the speed at which the technology is becoming a staple of British policing. Major funding is being allocated and hardware bought, while the British state is also looking to enable police forces to more easily access the full spread of its image stores, including passport and immigration databases, for retrospective facial recognition searches. Live facial recognition involves the matching of faces caught on surveillance camera footage against a police watchlist in real time, in what campaigners liken to the continual finger printing of members of the public as they go about their daily lives. Retrospective facial recognition software is used by the police to match images on databases with those caught on CCTV and other systems.

South Wales Police have revealed plans to deploy live facial recognition cameras in Cardiff during this year's Six Nations rugby internationals. The cameras will be placed at'key points' across the city centre, and will alert officers to anyone who is on a predetermined watchlist. The force claims that the cameras will help to'keep visitors safe'. 'The expansion of facial recognition cameras around the city centre really enhances our ability to keep visitors safe from harm,' said Trudi Meyrick, Assistant Chief Constable. 'Our priority is to keep the public safe and this technology helps us achieve that.'

As night falls in London, Georgina Rowlands and Anna Hart start applying makeup. Rowlands has long narrow blue triangles and thin white rectangles criss-crossing her face. Hart has a collection of red, orange and white angular shapes on hers. They're two of the four founders of the Dazzle Club, a group of artists set up last year to provoke discussion about the growing using of facial recognition technology. The group holds monthly silent walks through different parts of London to raise awareness about the technology, which they say is being used for "rampant surveillance."

The Metropolitan police will start using live facial recognition, Britain's biggest force has announced. The decision to deploy the controversial technology, which has been dogged by privacy concerns and questions over its lawfulness, was immediately condemned by civil liberties groups, who described the move as "a breathtaking assault on our rights". But the Met said that after two years of trials, it was ready to use the cameras within a month. The force said it would deploy the technology overtly and only after consulting communities in which it is to be used. Nick Ephgrave, an assistant commissioner, said: "As a modern police force, I believe that we have a duty to use new technologies to keep people safe in London. Independent research has shown that the public support us in this regard."