Cherie Blair has been recruited to lead one of the policy reviews set up by Labour leader Ed Miliband, the party said today.
The wife of former prime minister Tony Blair will examine how the UK can help women in poor countries get involved in business and public life.
Women are "the drivers of change across the world" but face serious barriers to realising their potential, the leading barrister and part-time judge said.
"They are far more likely than men to invest their incomes back into their families - helping to drive up better health standards and educational opportunities for their children, which in turn benefits the wider community. That's why working for the economic independence of women is vital to the fight against global poverty," she said.
"But there are so many barriers faced by women and girls in the developing world that they are often unable to participate in economic or political life and struggle to get access to healthcare and education for themselves, let alone their families.
"We need to look afresh at how countries like the UK, through their development efforts, can help make a real difference to the status and power of women in the developing world."
In 2008, she set up the Cherie Blair Foundation for Women which works to provide female entrepreneurs in Africa, South Asia and the Middle East with support including finance.
Her role for the party her husband led for 13 years was announced on the eve of the centenary celebrations of International Women's Day.
Shadow international development secretary Harriet Harman said: "The last 100 years have seen great progress for women and girls around the world but many challenges still exist.
"This policy group will examine how to tackle those challenges and ensure the empowerment of women and girls.
"Women don't want charity, they want justice and the opportunity to fulfil their own potential.
"I am delighted that Cherie Blair has agreed to chair this group. She is a committed campaigner for women and girls in the developing world. Her contribution will be invaluable."