British Foreign Secretary Boris Johnson will have to return a £500,000 (S659,700) advance to Hodder and Stoughton, after admitting that he no longer has time to write a book for them about William Shakespeare.

Johnson had been commisioned to write a biography of The Bard, to coincide with the 400th anniversary of his death.

Johnson had previously written The Churchill Factor: How One Man Made History, as well as The Dream Of Rome, a history of the Roman Empire.