Meghan Markle under fire for writing a letter to US Congress with her Duchess title

Prince Harry and Meghan Markle should be stripped of their titles, a US politician has demanded.

Republicans lashed out at the Duchess of Sussex after she wrote to members of the United States Congress and Senate calling for paid leave for new parents.

The letter - which was released on Wednesday - was on Sussex headed paper and Meghan signed it with her Duchess title, as per reports.

"Meghan's latest interference in US politics reignites the question in my mind as to why the Royal Family does not simply strip her and Harry officially of their titles, particularly since she insists on sending this under the pretence of being the Duchess of Sussex," Republican Congressman Jason Smith told the Daily Mail.

Lisa McClain slammed the Duchess: "Meghan Markle is incredibly out of touch with the American people and should stick to acting instead of trying to play politics. The last thing we need right now is wealthy celebrities pushing their liberal agendas on the American people."

Harry and Meghan kept their Sussex titles when they quit royal duties but agreed to stop using their HRH styles. Under the couple's agreement with the Queen they can still use their Duke and Duchess of Sussex titles.