A Spanish bar is encouraging clients to insult its staff and offering free drinks for original or hilarious abuse.

"When you come in after work, you can say swear at them and call them bastard or imbecile," said client Antonio Ossa, who told state news agency EFE the promotion by the "Casa Pocho" bar in the southern town of Cullera near Valencia seemed like a good idea to him.

Polish-born bar owner Bernard Mariusz said he thought people needed somewhere to release their frustrations at a time of economic crisis, employing the Spanish language's rich store of earthy obscenities.

"That way they won't let it out on their family," he said.