Queen Elizabeth fears Prince William could spark a constitutional crisis

British Queen Elizabeth II is reportedly worried that her grandson Prince William is threatening the line of succession.

The Duke of Cambridge is second in line to throne behind his father Prince Charles, while Prince George is third.

According to the Daily Mail, Queen Elizabeth has urged William to stop flying helicopters himself with his wife Kate Middleton and three children Prince George, Princess Charlotte and Louis on board because she is 'terrified' disaster could strike particularly in bad weather.

The monarch is feared an accident could threaten the line of succession.

As per unofficial rules, senior royals are not allowed to flying together, but the regulations have been relaxed since William's children were born, allowing them to spend more time together.

The Sun, citing a source close to monarch, had reported earlier this year 'It keeps the Queen awake at night, and she is understandably very worried. She knows William is a capable pilot but does not think it is worth the risk for all five of them to carry on flying together and can't imagine what would happen. It would spark a constitutional crisis.'

The report regarding Queen’s concerns resurfaces after Prince William flew a chopper, with daughter Princess Charlotte riding co-pilot on a very special trip to the Commonwealth Games.