Viewing figures for the interview could be on course to match the almost 23 million viewers who watched the 1995 Princess Diana interview where Harry’s mother lifted the lid on the breakdown of her marriage to Prince Charles.
The programme, which saw Meghan tell Oprah Winfrey a member of the royal family had raised “concerns” when she was pregnant about how dark her son Archie’s skin would be, was repeated on ITV after it was first shown in the US.
Watch: The key revelations from Meghan and Harry’s Oprah interview
Winfrey later said she had been asked to say the member of the family in question was not the Queen or Prince Philip leading to a rash of speculation online as to who said it.
It was just one of a series of bombshell revelations as the couple laid bare their brief lives as working royals with the Duchess saying she had suffered suicidal thoughts but her approaches to the monarchy for help were turned down.
Pressure is growing on the palace to respond but they have so far declined to comment on the claims with one source saying the main priority was to brief the Queen and they would not “get in some sort of tit for tat row over this”.
Meghan, the first mixed-race person to marry a senior British royal in modern history, also suggested her son was not made a prince because of his race – although rules set by George V meant he was not entitled to be one.
Pressure mounted on the palace after Labour leader Sir Keir Starmer said the allegations made by the duchess must be taken seriously.
Sir Keir said: “Nobody, but nobody, should be prejudiced (against) because of the colour of their skin or because of their mental health issues.”
Watch: Meghan's accusations of racism need to be heard, says Sir Keir Starmer
The claims made by the Sussexes in the interview are likely to make the divide between the California-based couple and the rest of the family unbridgeable for the foreseeable future.
Other revelations included Harry’s admission he has become estranged from his father, the Prince of Wales, saying: “I feel really let down”, but he added he would make it one of his priorities “to try and heal that relationship”.
Describing how she had been misrepresented in the press, Meghan said the Duchess of Cambridge had made her cry ahead of her wedding – the opposite of reports circulating ahead of the Sussexes’ nuptials that Meghan left Kate in tears at Princess Charlotte’s bridesmaid dress fitting.
The couple, who announced in February that they are expecting their second child, said they are due to have a baby girl in the summer.
The duke also added none of his relatives spoke out in support of Meghan following the racism he said she faced in the media.
“No-one from my family ever said anything over those three years. That hurts,” Harry said.
Commenting on her mental health crisis, when she felt she did not “want to be alive anymore”, the duchess said: “I went to the institution, and I said that I needed to go somewhere to get help. I said that, ‘I’ve never felt this way before, and I need to go somewhere.’
“And I was told that I couldn’t, that it wouldn’t be good for the institution.”
Watch: How Are People Reacting to the Harry and Meghan's Interview?