Donald Trump’s son has dropped a huge hint about how his dad would handle Prince Harry’s US visa row if he is to win the presidential election next week.

Just last week, the row over Harry’s US visa blew up once again after it was claimed the court battle over making his application public should be reopened because the US government made certain submissions in secret. After admitting to using marijuana, cocaine and psychedelic mushrooms in his controversial memoir Spare, a lawsuit from the conservative think tank Heritage Foundation argued that the Government should release records about the Duke’s visa US application to show whether his drug use was disclosed.

A judge later ruled it should remain private but Mr Trump, who is seeking reelection to the White House, previously suggested that the Duke of Sussex could face deportation over the ongoing controversy that he may have taken drugs. However, now in a new interview, Mr Trump’s son Eric suggested Harry’s visa would be safe because “no one cares” about him and that his wife Meghan is “pretty unpopular”.

Speaking to MailOnline, Eric said: “Truthfully I don’t give a damn about Prince Harry and I don’t think this country does either. My father loved the Queen and I think the monarchy is an incredibly beautiful thing.” He added: “‘I don’t give a damn if he did drugs. It means nothing. I can tell you that our father and our entire family has tremendous respect for the monarchy.”

Elsewhere in the interview he said Harry had appeared to have “gone off the deep end and it’s sad to watch” but praised his brother Prince William and added that his wife Kate has been “such a rock in the next generation of the family”.

His comments come a week after the Heritage Foundation made another court filing saying it was not granted access to private submissions made to the judge by the Biden administration. The 13-page motion was filed last Tuesday and says that the case was ‘unique’ and complex but adds there is “ample evidence of agency bad faith” meaning this “severely compromises [Heritage’s] ability to prepare arguments on appeal”.

The lawsuit was originally brought by the Heritage Foundation after a Freedom of Information request for the Duke’s records was rejected by the Department for Homeland Security (DHS). In his bombshell memoir, Harry confessed that cocaine “didn’t do anything for me”, adding: “Marijuana is different, that actually really did help me.” He also recounts an experience with magic mushrooms, saying: “I stared at the bin. It stared back. ‘What-staring? ‘ Then it became… a head. I stepped on the pedal and the head opened its mouth. A huge open grin.”

Speaking about his use of hallucinogens during an online chat with trauma expert Gabor Maté, Harry explained: “It was the cleaning of the windscreen, the removal of life’s filters — these layers of filters. It removed it all for me and brought me a sense of relaxation, relief, comfort, a lightness that I managed to hold back for a period of time.”

US visa applications specifically ask the individual about current and past drug use, which can have a detrimental impact on the progress of the application. Prolific drug use can lead to applications being rejected, however, immigration officers use their discretion against a range of factors.