The husband of murdered MP Jo Cox is using the sleepless nights following her death to write a memoir celebrating her life.
More In Common will be released on the eve of the first anniversary of the 41-year-old's brutal death at the hands of far-right extremist Tommy Mair.
Brendan Cox said her loss had left his life "more hectic than ever before", as the civil society campaigner simultaneously became a single parent to their two young children and the focus of great public interest.
"I wanted to write about Jo, but felt doing so was probably impossible because of all the pressures on my time," he told The Guardian.
"What I hadn't factored in was lack of sleep. Sleeping used to be one of the things I was best at, but since June that is no longer true.
"I often wake at 4am or even 3am nowadays and am unable to get back to sleep. So this book is very much the product of sleep deprivation."
Mrs Cox was murdered as she arrived for a surgery at her Batley and Spen constituency in West Yorkshire on the afternoon of June 16.
In the memoir Mr Cox says: "Today is the beginning of a new chapter in our lives.
"More difficult, more painful, less joyful, less full of love. I and Jo's friends and family are going to work every moment of our lives to love and nurture our kids and to fight against the hate that killed Jo.
"Jo believed in a better world and fought for it every day of her life with an energy and a zest for life that would exhaust most people."
The memoir will be published by Two Roads, an imprint of Hodder and Stoughton, on June 15.
The publisher described the memoir as a "moving and impassioned portrait of Jo - as daughter, mother, wife, sister, MP and activist - we see how much she gave and how much more she had to give, and her legacy of values and beliefs which will live on".
Mair was handed a whole life sentence in November. The 53-year-old shouted "Britain first" as he fired three shots at the Remain campaigner and stabbed her 15 times.
After Mair was jailed, Mr Cox said he had committed the "most incompetent and self-defeating" act of terrorism.