Prince William could pull the trigger and strip his estranged brother, Prince Harry, and his wife Meghan Markle of their “HRH” titles when he becomes king, according to palace insiders.

It’s no secret that the Prince of Wales, 42, has been embroiled in a bitter feud with his younger brother ever since the Duke and Duchess of Sussex quit royal life and moved to the US in 2020.

While their decision to step down as senior working members of the Firm came with the removal of taxpayer-funded security and no longer boasting keys to Frogmore Cottage, the pair were never formally stripped of their “His/Her Royal Highness” titles.

Still, the duo agreed they would no longer use their “HRH” titles after leaving the royal family.

Now, it appears Prince William is looking to re-evaluate the situation once he assumes the throne, sources tell the Daily Beast.

“It’s no secret William wants Harry more harshly dealt with. He thinks he has betrayed the family from top to bottom, which is the ultimate Windsor crime. It wouldn’t take much to provoke him to flex his muscles when he is king,” a palace insider told the outlet.

Despite William’s hardline position, the future king is respectful of the monarchy’s hierarchy — meaning his cancer-stricken father, King Charles III, still gets to set the tone, for now.

After the Sussexes had agreed to no longer use their HRH titles following their sensational departure from the palace, Harry and the “Suits” alum, 43, have since tested the waters in using their HRH titles from time to time.

Most recently, Markle took to social media to repost a message from the vice president of Ukraine addressing her as “Your Royal Highness.”

“Charles isn’t going to open a new front in the civil war on the basis of one Instagram post, and it’s not as if they are calling themselves HRH,” another source told the outlet. “I think everyone is pretty clear, at this stage, what the Duke and Duchess of Sussex’s position in the family is.”

Another insider added, “William has been given a great deal of influence on all areas of royal policy, but that cuts both ways and he respects his father’s rank.”

“Charles has a softly-softly attitude to Harry and Meghan, and so that’s the policy for now, but the gloves will be off when he inherits the throne. If they started using the HRH titles on a regular basis, he would take them away for good,” the source said.

The Post has reached out to Kensington Palace and Buckingham Palace for comment.

“It’s outrageous. Every time you think they can’t make it worse, they make it worse,” another source said of Markle’s Instagram repost featuring the HRH title.

“The deal with the HRH was a way to stop them cashing in while letting them walk away with pride and dignity and trust, and now Markle is using her HRH on a website which seems to exist to sell jam.”

In recent years, the UK government has faced calls to intervene and strip the couple of the titles. Parliamentary bills had also been put forward, though none were enough to get over the line.

“It’s actually quite a clever way of testing the water, because there is deniability there, she can say, ‘Well, I just wanted to publish this nice letter to raise awareness for Ukraine, and oops! they got my name wrong — but oh, actually, now I think of it, I never gave the title up anyway, and maybe I will start using it again,’” another source said.

“It’s a step in the wrong direction, basically, away from the agreement. You’d have to be an idiot to believe that she didn’t know exactly what she was doing when she posted that message, unedited, to her stories.”