The Duchess of Sussex has criticised the constraints she faced when a working royal and said it was “liberating” to be able to “say yes” to Oprah Winfrey’s request for an interview.

Meghan has taken another swipe at the institution of the monarchy in the latest clip released from her interview with the US chat show queen, saying she and Harry now have “the ability to make our own choices”.

The royal family was described as a “construct” which was different to “what people imagine”, suggesting life within palace walls was not what she had expected.

Royal aides are likely to be concerned what further revelations are to come from the duke and duchess when the full two-hour chat is aired on the CBS network on Sunday evening in the US.

The prospect of the interview is the latest dramatic development within the monarchy, which has seen allegations of bullying made against Meghan, which her lawyers have denied, and the Duke of Edinburgh being treated in hospital for a heart condition.

Winfrey revealed she first approached the duchess for an in-depth chat a few months before her May 2018 wedding but was turned down with the proviso “perhaps there will be another time”.

Asked what was “right” about this moment to talk, Meghan paused for a few moments and replied in the clip aired on CBS This Morning: “Well, so many things. That we’re on the other side of a lot of…a lot of life experience that’s happened.

“Also that we have the ability to make our own choices in a way that I couldn’t have said yes to you then. That wasn’t my choice to make.

“As an adult who lived a really independent life to then go into this construct that is…different than I think what people imagine it to be, it’s really liberating to be able to have the right and the privilege in some ways to be able to say yes.”

Winfrey goes on to suggest that it was liberating for the duchess “not to have to consult with anybody at this point?”

Meghan replied: “Yes, to be able to just make a choice on your own. And to be able to speak for yourself.”

The duchess has already accused The Firm – as the royal family is sometimes known – of “perpetuating falsehoods” about her and Harry in a clip released on Thursday.

And in the latest instalment, Meghan comments on the controlling nature of the monarchy, with members of the “comms” or communications team being present during her first chat with Winfrey.

She said: “Well, I remember that conversation very well. I wasn’t even allowed to have that conversation with you personally, right. There had to be people from the comms sitting there…”

The chat show host questioned the circumstances of the call, saying: “There were other people in the room when I was having that conversation?” and the duchess replied: “Yeah, even on that call.”