Conservative leader David Cameron tonight said his son's death had left a hole in his family's life "so big that words can't describe".

The Witney MP and his wife Samantha lost their eldest son Ivan - who had cerebral palsy and a rare form of epilepsy - on Wednesday morning.

Mr Cameron tonight made his first statement since the six-year-old's death, thanking people for the outpouring of support and sympathy.

In it he paid tribute to Ivan and revealed movingly how the little boy had so enriched the Camerons' lives.

Mr Cameron said: "We always knew Ivan wouldn't live forever, but we didn't expect to lose him so young and so suddenly.

"He leaves a hole in our life so big that words can't describe it.

"Bed time, bath time, meal time - nothing will feel the same again.

"We console ourselves knowing that he won't suffer anymore, that his end was quick, and that he is in a better place.

"But we all just miss him so desperately."

He added: "When we were first told the extent of Ivan's disability I thought that we would suffer having to care for him but at least he would benefit from our care.

"Now as I look back I see that it was all the other way round.

"It was only him that ever really suffered and it was us - Sam, me, Nancy and Elwen - who gained more than I ever believed possible from having and loving such a wonderfully special and beautiful boy."

Thousands of people have sent messages to Mr and Mrs Cameron, including the Queen.

Mr Cameron's statement was sent in his weekly email to party activists and staff.

Thanking them, Mr Cameron said: "Sam and I have been overwhelmed by all the letters, cards, emails and flowers we have received about Ivan.

"Sending an e-mail this week just gives us both a chance to say a big 'thank you'.

"It means a lot to know that others are thinking of us and him."

Ivan was taken ill on Tuesday night and rush to St Mary's Hospital in Paddington, West London. He died at 6.30am on Wednesday.

A private family funeral will be held in west Oxfordshire on Tuesday.

Several churches in his constituency will be saying special prayers for the family tomorrow.