He continued to say: "And far worse is to come if he continues to try stonewall his way out of any accountability re the serious allegation against him and his relationship with Epstein/Maxwell."
The tweet was a direct reaction to Buckingham Palace's statement that the Duke has been stripped of all royal titles and military honours.
"The Duke of York will continue not to undertake any public duties and is defending this case as a private citizen," the Palace statement said.
In a separate tweet, Morgan addressed Queen Elizabeth, showing empathy for the monarch who only recently lost her husband.
"I feel so sorry for the Queen. In the last year she's lost the love of her life, endured the monarchy she heads being repeatedly trashed by the Sussex clowns, & suffered what must be any mother's nightmare over Andrew's deplorable conduct."
He ended the tweet by saying, "She's 95, and deserves so much better."
The former Good Morning Britain host has previously spoken on the matter of Prince Andrew, with The Sun reporting Morgan saying: "Will vile sex trafficker Ghislaine Maxwell now sing like a canary to avoid spending the rest of her life in prison? If she does, there could be a lot of rich, powerful & famous people sweating tonight ... and not sweating." As a dig to the duke's earlier defence claiming he doesn't sweat.
In light of Giuffre's case going ahead in American courts, a source close to the accused royal said he would "continue to defend himself" against Giuffre's allegations, the Mail reported.
The source said: "Given the robustness with which Judge Kaplan greeted our arguments, we are unsurprised by the ruling. However, it was not a judgement on the merits of Ms Giuffre's allegations. This is a marathon not a sprint and the duke will continue to defend himself against these claims."
It came as reports suggested he could avoid a trial by using the sale of his £18 million ($36m) Swiss chalet to try to pay off Giuffre with at least £10m ($20m) of the proceeds.