A police boss urged the BBC's Newsnight programme not to insult the Welsh language again - and to seek the opinions of real experts if they discuss the subject in future.
North Wales Police and Crime Commissioner Arfon Jones (pictured) hit out after the late night programme provoked outrage when it asked whether the Welsh language was a "help or hindrance to the nation".
The BBC has since expressed its regret and conceded the programme would have "benefited from more thorough analysis and debate".
Mr Jones has written in Welsh to the programme's editor, Ian Katz, seeking an assurance the same mistake will not be repeated.
The discussion on August 9 did not have anybody who could speak the language involved, with contributions from author Julian Ruck and Ruth Dawson, Wales Editor for the independent news and analysis website The Conversation.
At the start of the programme presenter Evan Davis asked of the language: “Is it the government’s job to promote it and is it a help or a hindrance to the nation.”
He later went on to say: “We will see how people will choose to speak it and how many will have it as a hobby, and how many speak it as their main language.”
In his letter Mr Jones accused Newsnight of discussing the language in "a childish, derogatory and irresponsible way" adding they had managed to raise the hackles of a whole nation.
He went on: "There was a weak, unconvincing apology the following night that did not persuade anybody that there was any real regret on your part.
"Asking whether the language is a hindrance is totally unacceptable, and it's irrelevant in any context. The Welsh language exists. People speak it as their first language every day.
"Should we make those who speak the language feel irrelevant and a hindrance or should we do our best to safeguard the language as an integral part of the tapestry of life in our little corner of the world?
"The BBC would not dare question whether a person's religion or ethnicity was a hindrance. Think of the justifiable outrage there would be to such an insult! How therefore can a public body that we pay dearly for justify questioning whether a language, especially one that is native to these islands and has existed well before English, is a hindrance?
"You could argue that slighting someone's language is more of an insult than questioning their religion because language is an inextricable part of who each one of us is as an individual.
"I would like to convince you that the Welsh language is integral in my work and a bit more important than the "hobby" Evan Davies referred to on the programme.
“As a fluent Welsh speaker in an elected position with responsibility for £143 million in spending, I believe passionately that I need to uphold my responsibilities to those who want to receive services in Welsh or English; neither language is treated less favourably than the other.
"Every other public body in Wales has a statutory duty to ensure that the Welsh language is not treated less favourably than English. Even though the majority of people in North Wales are able to speak English, dealing with a public body in your second language is different to communicating in your first language.
"In future I therefore call on you, as somebody who works for a public body, to carry out your moral responsibilities in relation to equality and to do your homework before any such programme is broadcast.
"If you deal with Welsh again it would be good if you could show some respect to the language, and the people who speak it, by making sure it is discussed by experts and not by contributors who can't speak the language and have very little knowledge about the subject."