In an attempt to highlight the pain experienced by dairy cattle, protesters are allowing themselves to be branded with the number 269. But is it even legal?

Animal-rights protesters have long been masters at courting both attention and controversy in their quest to put an end to what they perceive as cruel farming practices.

Becky Folkard, a 34-year-old vegan from Hampshire, is promising to perform the latest form of protest today at a staged event in London where she will "hot brand" three fellow protestors to highlight the pain inflicted on dairy cattle when they are branded.

Folkard will burn the number "269" on the bare chests of three volunteers – two anonymous women and a 24-year-old protestor called Ben Hannah – using a red-hot branding iron. This form of action originated in Israel last year when protesters released a video of volunteers being branded with the number 269 – in tribute to a calf they encountered on a farm. The idea has now spread virally across the world culminating in a global "We All Are 269" day, with events planned in cities including Melbourne, Frankfurt, Lima and Washington DC.

"My initial reaction was admiration," says Folkard. "I don't see it as shocking, although I accept others will. I immediately wanted to be involved and thought: 'I couldn't do the branding, that sounds terrifying.' But then I thought about it more and realised why not? ... If one person goes away and researches a vegan lifestyle because of this it will have been worth it."

There still seems to be some confusion about whether this form of protest is legal. The protestors insist it is legal because all the participants have consented and they say they have informed the police in advance. An RSPCA representative told reporters: "A lot of people would feel that what they are doing is extreme but if they want to do it they can."

But Joseph Keating, the National Farmers Union's livestock adviser, was perplexed by the planned protest: "I've never seen hot branding done in this country. It has been outlawed for a generation. I've only seen it in old western films. Cattle are now identified with ear tags from birth, as are sheep. They are applied with plier-like tools. There's no anaesthetic but the process is very quick and the animal barely notices. It's just like an ear piercing. Pigs get 'slapped' with an ink mark, but again, this is only momentarily painful."

Some dairy farmers might freeze-brand their animals, says Keating – a process that kills the hair follicles or the skin's pigmentation cells rather than deeply scarring the skin itself – but many farmers are now turning to neck or foot collars with electronic chips inside to more accurately monitor and manage their herds.

"Hot branding stresses the animal needlessly and also potentially damages the meat," he says. "It was introduced many centuries ago to guard against rustling. But we've moved on a bit since then."