The man, in his early 20s, was found shortly after midnight with a nail through each hand. Two vans, one belonging to the injured man, were found on fire in the car park near Dundarave Park.
Alliance North Antrim MLA Sian Mulholland said it was an “especially appalling” incident.
“My first thoughts are with the victim of this serious assault,” she said.
“The nature of this attack was especially appalling and has left the victim with potentially life-altering injuries. It is not acceptable under any circumstances to brutally assault someone in this manner and I hope the man makes a full recovery. There is no place for this violence in Bushmills, North Antrim or anywhere else in Northern Ireland.”
“Those behind this attack are clearly extremely dangerous individuals, who need taken off the streets immediately,” added Alliance Causeway Councillor Richard Stewart.
“This assault has shocked the local community with its brutality and must have been terrifying for the victim. There is no justification for this level of violence and destruction to property.
"I would appeal to anyone with information on this to contact the police with it immediately.”