A British man planned to attack a Pride event in Northwest England with a machete and air rifle, jurors heard this week.

On Tuesday, prosecutors claimed 20-year-old Ethan Stables "was enraged" when he learned that the New Empire pub in Cumbria was hosting an LGBT event on June 23, 2017.

Stables began his reconnaissance of the bar that same day, taking notes and snapping photos, with the aim of launching an attack that night. He reportedly bragged about his plan on a white-supremacist Facebook group, writing, "I'm going to war tonight... I'm going to walk in with a fucking machete and slaughter every single one."

"I've had enough. I don't want to live in a gay world," he added. "Tonight is going to be a good night and the beginning of the end."

Tipped off by a woman who spotted his posts, police arrested Stables at about 10pm, while he was carrying out his final recon before he planned to return with a machete, knives, an axe, air rifle, and a BB gun.

Prosecutor Jonathan Sandiford described Stables as a “white supremacist and Nazi [with] a deep-seated hatred of black, Jewish, Muslim and especially gay people” and claimed he spent seven months researching explosives with the goal of creating an improvised explosive device. "His purpose in these acts of preparation was to launch a murderous attack on members of these communities. In particular... people who were gay."

But defense attorney Patrick Upward denies his client is white supremacist, calling him more of a "white fantasist" who daydreams about hurting minorities with no real intention of acting on his plans.

"He never expected anyone to believe what he had to say," Upward told the court, adding that Stables' favorite uncle is gay and his best friend is black.

Stables, who allegedly has been diagnosed with Asperger's Syndrome, has pleaded not guilty to preparing terrorist acts and making threats to kill.