A report in the Sunday Times says Prince Charles is anxious for his oldest son to become fluent in the language.

Prince William is being taught at Eton and getting extra lessons from Manon Williams, who was an assistant private secretary to Prince Charles before taking up a post with the new Welsh Assembly.

Ffion Hague taught her future husband the Welsh national anthem

Teaching Welsh to public figures is becoming something of a tradition for Manon Williams' family.

Her sister, Ffion Hague, is credited with teaching her future husband, William, the words to the Welsh National anthem when he was Welsh Secretary and she was his assistant private secretary.

In May, Prince Charles showed he still had a command of the language when he made a speech in Welsh at the opening ceremony of the new Welsh Assembly.