Charles sparked a diplomatic spat last week by comparing Russian President Vladimir Putin to Adolf Hitler, with some lawmakers calling for the 65-year-old prince to keep his personal opinions private.
But he showed today he is determined to voice his opinions, calling on an audience of global business leaders to take tough choices over climate change and capitalism even if it made them unpopular.
He said the world was at the mercy of people vociferously and aggressively denying the current operating model was accelerating climate change which could destroy the world.
"... we can choose to act now before it is finally too late, using all of the power and influence that each of you can bring to bear to create an inclusive, sustainable and resilient society," he said in a speech in London to a conference entitled Inclusive Capitalism.
He added: "There will, of course, be hard choices to make, and, take it from me, in the short term, you will not be popular with your peers, but if you stand firm and take the kind of action that is needed, I have every confidence the rewards will be immense."
He made no reference to comments reportedly made in a private conversation in Canada last week in which he was said to have compared Putin's actions in Ukraine to those of Hitler during World War Two.
Putin has accused the prince of unacceptable and unroyal behaviour for remarks that a British newspaper reported he made to a Jewish woman who fled Poland during the war.
The prince's office has declined to comment on the reported remarks because they were made during a private conversation.
Traditionally, Britain's royal family does not voice political views in public, with the head of state merely a constitutional figurehead. During her long reign, Queen Elizabeth, 88, has never aired personal sentiments.
But Charles has often courted controversy by voicing strong views on the environment, architecture and social affairs.
He told Tuesday's conference, where others speakers include former U.S. President Bill Clinton, International Monetary Fund Managing Director Christine Lagarde and Bank of England Governor Mark Carney that "we stand at a pivotal moment in history".
He highlighted the growing plight of the world's most vulnerable people and the unprecedented environmental change that he said was undoubtedly compounded by man-made global warming and the great strain put on nature's life-support systems.
"These changes threaten to undermine all of the progress we have achieved, unless we can create a much more sustainable and inclusive approach," he said.
"If there is a price to pay for achieving the necessary transformation, it will be our abandoning of the next, seemingly easy, short-term solution that our current form of capitalism thinks is necessary and, instead, focusing on approaches that achieve lasting and meaningful returns."
