Sarah back in the limelight as Brown holds talks in New York

Gordon Brown held talks in New York today on the worldwide economic crisis and tackling poverty in the developing world.

He was accompanied by his wife Sarah, who took to the global stage in the campaign to fight killer diseases and increase education in the world's poorest countries.

She co-hosted a dinner last night for influential women, including many first ladies, to raise awareness of the need to improve childbirth support in the third world.

Less than 48 hours earlier, Mrs Brown had thrown herself into the media spotlight with a passionate defence of the Prime Minister ahead of his keynote speech to Labour's annual rally in Manchester.

She then flew with Mr Brown to America and is now seen as playing an increasingly important role in his fight to remain Prime Minister.

While controversy relentlessly followed Cherie Blair during her husband Tony's premiership, Mrs Brown is now emerging as a valuable asset to offset his dour image.

Mrs Brown held discussions with a series of influential women at the reception last night including Rupert Murdoch's wife Wendi Deng and Jordan's Queen Rania.

Meanwhile, Mr Brown was today due to hail a new $3billion drive to eradicate deaths from malaria in the developing world by 2015 at an emergency United Nations summit on world poverty and disease.

The initiative, to develop a vaccine and distribute bed nets and sprays, is expected to save the lives of one million people every year.

The Prime Minister and Microsoft boss Bill Gates were announcing the package at the UN gathering attended by 90 world leaders to discuss the Millennium Development Goals.

But Mr Brown's focus was being shifted to the economic crisis gripping the developed world, talking to Wall Street hedge fund chiefs about the turmoil in the markets. However, he was not due to meet US Treasury Secretary Hank Paulson, sparking suggestions that he had been snubbed.

Despite reports that Mr Brown had requested a meeting, a Downing Street official said: "The Prime Minister will be in New York and Hank Paulson will be in Washington, so they won't be meeting."