Actor Colin Firth is shown in a scene from The King's Speech

His performance as a stuttering King George VI has already won him a best actor Oscar.

Now Colin Firth’s royal role could see him honoured by Her Majesty herself.

The 50-year-old has been nominated for the Queen’s Birthday Honours list and looks set to pick up a knighthood.

Firth, pictured, will not learn if has been honoured until a week before the list is announced in June. Nominations have already closed and are now being considered by a committee led by the Cabinet Office.

But a source hinted the actor is likely to become Sir Colin.

The source said: “Colin has been a great ambassador for Britain throughout his career and his sensitive portrayal of King George VI has won him much admiration among the Royal Family - and of course, the film’s many fans.”

The Queen has had a private screening of The King’s Speech, which also picked up best film award, and best director for Tom Hooper at the Oscars on Sunday.

Firth, who arrived back in Britain yesterday with his wife Livia, 41, his Oscar in tow in a small suitcase, may have to wrestle with his conscience over accepting an honour if he is awarded one. During an interview with Piers Morgan last month, the actor admitted that the fact the Royal Family is unelected was “a problem” for him.

Bookmakers Ladbrokes are offering odds of 4/1 on Firth being knighted within the year.

Last night the Cabinet Office confirmed that discussions were ongoing, but refused to comment further. Buckingham Palace declined to comment.