Cherie Blair has stepped in to help fund the Women's Prize for Fiction - previously the Orange Prize - while it looks for new sponsors.
Organisers said the prize, which was sponsored by the communication company up until last year, will be privately funded while "headline sponsorship negotiations for 2014 and beyond are concluded".
Other backers joining the former Prime Minister's include entrepreneur Martha Lane Fox and writer Joanna Trollope.
Kate Mosse, who chairs the prize board, said: "We were overwhelmed with interest from potential headline sponsors. However, it became clear sponsorship budgets for next year were already committed, so we took the decision to privately fund the Prize for 2013 while we finalised our arrangements for 2014 and beyond. We are delighted that such a wide range of people are supporting this exceptional year and thank them for their support."
American novelist Madeline Miller won the 2012 prize - the last time it was formally known as the Orange Prize for Fiction - with her debut novel The Song of Achilles.
Next year's prize will be awarded on 5 June at the Royal Festival Hall, London, after the judges, who include actress Miranda Richardson and writer JoJo Moyes, have picked a winner.
Richardson said: "This is a new departure for me and I am honoured to be working with judges who combine fine minds with, I suspect, great good humour.
"I look forward to sharing with them the delights of finding new insights into our existence, through the unique voices of the women entering this year's competition. It will be rigorous, and hopefully, fun. It is an exciting responsibility and I very much look forward to beginning the journey."
The winner will receive the usual prize - a cheque for £30,000 and a limited edition bronze figurine known as a Bessie.
Previous winners include Zadie Smith, Linda Grant and Lionel Shriver.
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