Gordon Brown will warn today that the historic commitments made by the United Nations in 2000 to relieve poverty in the developing world are in danger of being missed.

The Prime Minister will reaffirm his commitment to the Millennium Development Goals in a speech to the Lambeth conference of Anglican bishops which moves temporarily from Canterbury to London today. He will say that while good progress is being made on some targets – such as on the eradication of extreme poverty – other areas including education and sanitation need urgent improvement.

Mr Brown staved off an attempt to water down the G8 commitment at the Gleneagles summit three years ago that the world's richest economies will double aid to Africa to $25bn a year to 2010. But he is concerned that the wider effort by the UN is behind schedule.

As well as eradicating extreme poverty, the development goals are achieving universal primary education, promoting gender equality and the empowerment of women, reducing child mortality, improving mental health, combating HIV, Aids, malaria and other diseases, ensuring environmental sustainability and developing a global partnership for development.

The latest World Bank-IMF report warns that most countries will fail on the goals. Many parts of the world are on course to halve extreme poverty by 2015. But the aims of cutting child and maternal mortality are looking highly unlikely. Primary education, sanitation and nutrition goals also look likely to be missed.

The World Bank estimates that food price increases – 74 per cent for rice over the past year, and 130 per cent for wheat – will drive at least another 100 million people into deep poverty.

The Archbishop of Canterbury, Rowan Williams, will praise the progress achieved by Mr Brown so far, but add a new challenge, urging world leaders to invest in and strengthen their partnership with the church worldwide, so that its extensive delivery network for education and health care, alongside other faiths, is fully utilised in the eradication of extreme poverty.

The World Bank says 70 per cent of Africans live in absolute poverty – less than $1 a day – while 90 per cent live on less than $2 a day.