Downing Street's top civil servant has died of cancer, David Cameron has said.

Speaking at Prime Minister's Questions, Mr Cameron paid tribute to "one of the most loyal, hard-working, dedicated public servants" as he told MPs Chris Martin had died earlier today.

Mr Martin, who was Principal Private Secretary (PPS) in Number 10, was awarded the Insignia of a Commander of the Royal Victorian Order on Saturday.

Mr Cameron told MPs: "Everyone in this House and many watching at home know from Yes, Prime Minister the central role that Bernard, the prime minister's principal PPS, plays in the life of the prime minister and of No 10 Downing Street.

"This morning, my Bernard, my principal private secretary, died of cancer.

"Chris Martin was only 42. He was one of the most loyal, hard-working, dedicated public servants that I have ever come across.

"I have no idea what his politics were but he would go to the ends of the earth and back again for his prime minister, for No 10, and for the team he worked for.

"Today, we are leaving the seat in the officials' box where he used to sit empty as a mark of respect to him. We think of his wife, Zoe, his family, the wider No 10 family - because it is a bit like a family - and we feel we have lost someone between a father and a brother to all of us.

"Whatever happens, we will never forget him."

Labour leader Jeremy Corbyn said: "On behalf of the Opposition, could I also express my condolences to the family of Chris Martin on his death.

"The Prime Minister told me how ill he was on Remembrance Sunday and I am pleased he was able to visit him at that time.

"Also, on behalf of many members who worked with Chris Martin when we were in government, appreciate very much the professional work he did in the very highest and best traditions of the civil service in this country.

"If our condolences could be passed on, I think that would be very helpful."

A statement issued on behalf of Mr Martin's wife Zoe Conway said: "Chris was the kindest and most supportive person I have ever met. He always helped you to be the best person you could possibly be."

His family said in a statement: "We are distraught at the loss of a dear husband, son and brother and proud of his achievements beyond measure. Most of all we will miss him."