Brown: Why I'm proud of my mother

In a Mother's Day newspaper article, the PM said he would spend the day thinking about his mother, who died aged 86 in 2004.

And also he said he was planning a rare treat for his wife Sarah - by making her breakfast.

Mr Brown remembered Jessie Elizabeth Brown as a mother "of the 1950s Scottish variety - no nonsense, no fuss, just strong boundaries and deep love" but also "a ferociously intelligent woman, with a particular gift for maths".

It was her skill with numbers which led to the former Aberdeen schoolgirl being asked to come to London to help break enemy codes as part of the war effort.

Mr Brown recalled: "She never told me until I was a lot older that during the war she'd used that talent working with the people who were breaking German military codes.

"She was one of the thousands of people celebrating outside Buckingham Palace the day the war in Europe ended - and she later joked to me that she had worked in Whitehall long before I did.

"I was proud of her then and I'm proud of her now."

But he also voiced pride in her work raising a family with clergyman husband John in Kirkcaldy, "always quietly getting on with supporting neighbours, volunteering for charity, helping run the church and trying all the while to keep three unruly boys free of scraped knees, missed homework and torn clothes".

The PM said that he and his brothers appreciated their mother all the more when she was in hospital for a few weeks and they had to live on their father's cooking.