A speaker interrupted transmissions for six minutes and claimed to be a representative of an "Intergalactic Association". Reports of the incident vary, some calling the speaker "Vrillon" or "Gillon", others "Asteron". The voice, which was disguised and accompanied by a deep buzzing, broke into the broadcast of the local ITV station Southern Television, over-riding the UHF audio signal of the early-evening news being read by Andrew Gardner from ITN to warn viewers that "All your weapons of evil must be removed" and "You have but a short time to learn to live together in peace."
The interruption ceased shortly after the statement had been delivered, transmissions returning to normal shortly before the end of a Looney Tunes cartoon. Later in the evening, Southern Television apologised for what it described as "a breakthrough in sound" for some viewers. ITN also reported on the incident in its own late-evening Saturday bulletin.
The broadcast took over the sound only, leaving the video signal unaltered.
At that time, the Hannington UHF television transmitter was unusual in being one of the few transmitters which rebroadcast an off-air signal received from another transmitter (Southern Television's Rowridge transmitter on the Isle of Wight), rather than being fed directly by a landline. As a consequence it was open to this kind of signal intrusion, as even a relatively low-powered transmission very close to the receiver could overwhelm its reception of the intended signal, resulting in the unauthorized transmission being amplified and rebroadcast across a far wider area. The IBA stated that to carry out a hoax would take "a considerable amount of technical know-how" and a spokesman for Southern Television confirmed that "A hoaxer jammed our transmitter in the wilds of North Hampshire by taking another transmitter very close to it." However, like the Max Headroom broadcast signal intrusion a decade later, the identity of the intruder was never confirmed.