Witney MP and Conservative Party leader David Cameron today spoke about the death of his son, Ivan, and thanked well-wishers for the "comfort" they had provided for his family.

Returning to the House of Commons chamber for the first time since his six-year-old son died a fortnight ago, Mr Cameron said he looked forward to the day when he could think "happy thoughts" about Ivan's life, rather than feel "sorrow" at his death.

Prime Minister Gordon Brown, who also suffered the loss of his first child, Jennifer, welcomed Mr Cameron back, saying he understood the grief he had been going through.

Mr Cameron first told Commons' Speaker Michael Martin: "Can I thank you for the kind words you said a fortnight ago about the loss of my son Ivan.

"I particularly want to thank the Prime Minister for what he said.

"It came straight from the heart and it meant a great deal to Samantha and to me.

"We've had letters from right across the House of Commons and from thousands of people in the country and it has been a great comfort to know that others are thinking of us.

"A lot of letters have come from families who themselves have lost children.

"If there's a common theme in them, it is that while the loss never goes away, there does come a day where you look back at your child's life and think happy thoughts at their life, rather than feel sorrow at their death.

"I hope that day will come for us too."

Head bowed, Mr Brown said: "Let me welcome you back and I understand the grief that you and your family have been going through."

Two weeks ago Prime Minister's Questions was cancelled and replaced by brief tributes after Ivan's sudden death.

Liberal Democrat leader Nick Clegg told Mr Cameron: "On behalf of all of us on these benches, we sincerely hope that you and your family have the time and the space to cope with the terrible loss you have suffered."