The Prince of Wales says he will give the best talk on topics that he / she feels strongly about when he becomes king, as " bad ".
He has campaigned on issues such as the environment for decades but said he would not do the same thing as a monarch.
Speaking in the BBC documentary program to mark his 70th anniversary, Prince Charles said the idea that he would continue to make interventions was "nonsense".
He said he would have to act within "constitutional parameters".
What has it said?
In the documentary, Prince Charles was asked about his campaign, which some people have described as "meddling".
John Bridcut, a documentary maker, who followed the royal for 12 months, said Prince Charles "a little bit" on the use of the word "meddling" and rather he would think of his interventions as "stimulating".
He said the heir to the throne: "If he thinks worried about the inner cities as I was 40 years ago, then if that and I think proud of it. "
He said that the roles of the Prince of Wales and the king were completely separate.
"It's crucial to remember that there's only room for one sovereign at a time, not two," he said.
"So you can not be the same as the sovereign if you are the Prince of Wales or the heir.
"But the idea, somehow, I'm going on exactly the same way, if I have to succeed, totally because both of them – both situations – are quite different."
He asked if his public campaign would continue, he said: "No, no. I'm not so stupid.
Mr Bridcut said: "People who think they are hanging, eager to be a king, are a very mistaken.
"Something that he dies to take for granted, because inevitably, will only rise after his mother's death."
Why is this significant?
By Nicholas Witchell, the BBC's Royal Correspondent
He has spent his adult trying, as he puts it, "to make a difference". This has often led the Prince of Wales to talk about topics that he / she feels deep about: the environment, GM crops, inner cities, architecture, education, homeopathic medicine and others.
On occasions, it has caused inflammation within government departments who had to respond to "black glass" handwriting letters, always courteous but often short, some issue that has come to the attention of the prince.
They all have a great concern. Does Prince Charles fully realize that when he gets his mother and becomes the king of Britain, will these interventions have to give her the best?
Those who know it has said for years in private that he fully understands that he would have to stop his "campaigning" as a king.
Prince Charles himself has always been deceived by saying so much in public. He is said to have felt that any reference to how he would act as a king would be disrespectful to his mother.
However, with the Queen now in her 93 years, and with Prince Charles to celebrate her 70th birthday, he finally said – in public and clear – he acknowledges his interventions on Issues of public debate have to stop as soon as he becomes king.
"You're acting," he said in the BBC documentary, "within the constitutional parameters."
It is reasonably assumed that his certainty will be heard with some relief in Whitehall and power corridors.
What has he campaigned?
The Prince of Wales has campaigned for urban design and traditional architecture for many years.
He led to the throne of the Founding Institute of the Prince of Wales in 1986, now known as The Prince's Foundation.
In 1992, he said: "I was not particularly eager to see this country, I think of and love it, disappears under a welter of a great deal."
The throne of the throne has talked passionately about climate change and environmental sustainability.
In 2017, he said that people have to live in harmony with their environment.
He added: "Failing to do that, and I fear that we are already very close to doing this, are proving catastrophic."
BBC environmental analyst Roger Harrabin said: "The prince warned a decade ago about climate change caused by humans.
"It was controversial to those at the time but now there is a scientific consensus on the threat."
Conservation of wildlife
Prince Charles has been a constant fan to life and wildlife conservation campaigns.
In 2018, he said: "With the current rate of losing biodiversity now running 1,000 natural rates, it seems that we have started to start the sixth major disappearance of the planet and still be completely destroyed by hell; what we have left. "
Prince Charles has provoked some criticism about his homeopathy support – treatment is based on the use of very weak substances that claim to help the body improve itself.
In 2015, he said in the international gathering of scientists and government officials, he was handling his own cattle and sheep with homes.
Clarence House later said: "Homeopathy is used per case in Home Farm, in conjunction with more conventional medicine, to reduce dependence on antibiotics."
- Prince, Son And Heir: Charles At 70, screened on BBC One on Thursday, November 8th, at 21:00.