Gordon Brown said he has apologised to the grieving mother of a soldier killed in Afghanistan for "any unintended mistake" in a hand-written letter of condolence.
The Prime Minister spoke by telephone with Jacqui Janes after learning of her distress over the message, sent after her son Jamie, 20, of the 1st Battalion The Grenadier Guards, was killed by an explosion on October 5, which began "Dear Mrs James".
In a statement, Mr Brown said: "I take very seriously my responsibility to the bereaved.
"Every time I write a letter to mothers and fathers and partners who have suffered bereavement to express my sincere condolences, it is a moment of personal sadness to me.
"And I am in awe of the bravery and sacrifice of the men and women of our armed forces.
"I send a hand-written letter to every family and I often write to more than one member of the family. I have telephoned Jacqui Janes to apologise for any unintended mistake in the letter."
He went on: "To all other families whom I have written to, I can only apologise if my handwriting is difficult to read.
"I have at all times acted in good faith seeking to do the right thing. I do not think anyone will believe that I write letters with any intent to cause offence."