The Archbishop of Canterbury, Dr Rowan Williams, will join forces with Prime Minister, Gordon Brown, at a rally in Lambeth Palace later today to warn governments around the world that starvation, disease and death will follow unless they keep their pledges to deliver on eight Millennium Development Goals (MDGs).

The eight pledges, agreed by world leaders at the United Nations at the turn of the Millennium, commit world leaders to eradicate extreme poverty and hunger, achieve universal primary education, promote gender equality and empower women, reduce child mortality, improve maternal health, combat HIV/Aids, malaria and other diseases, ensure environmental stability and develop a global partnership for development.

The warning to world leaders will come in a letter being handed to Gordon Brown by the Archbishop. In it, Dr Rowan Williams will argue that 'this generation has a genuine opportunity to eradicate extreme poverty' but stress that the current rate of progress will suggest that "most of the MDGs agreed by global leaders in 2000 to halve poverty by 2015 will not, as things stand, be fulfilled by this deadline - and in fact, risk never being achieved at all".

The Archbishop will welcome the efforts of the UK government and Gordon Brown, in "leading the community of nations in the EU and at the UN in tackling global poverty and inequality, and in raising awareness through the 'Call to Action' to accelerate progress to deliver the goals." He will also stress the important role churches can play in partnership with governments to help them deliver on their promises, highlighting the church's "extensive delivery network for education and health care".

The rally at Lambeth Palace follows a march through Whitehall and past the Houses of Commons by around 650 bishops, their spouses, parliamentarians, representatives of NGOs, diplomats, leaders of other Christian groups and representatives of other faiths. Bishops too old to march will make their way in the procession on rickshaws.

When the Archbishop hands his letter to the Prime Minister he will be flanked by the leader of the Roman Catholic Church in England and Wales, Cardinal Cormac Murphy-O'Connor; the Chief Rabbi, Sir Jonathan Sacks and leaders of other faiths including Sir Iqbal Sacranie and Dr Indarjit Singh.

The rally at Lambeth Palace is one of a number of events being planned to highlight the lack of progress being made on delivering the MDGs. To coincide with the London march and rally, Anglicans in the United States are holding a 'Virtual March for the MDGs' to inundate Congressional e-mail in-boxes, while in Canada, Anglicans will lobby members of the Canadian Parliament.

The UN Secretary General, Ban Ki-moon, has called a special 'high level meeting' in September to 'discuss specific ways to energise our efforts' and 'send a strong message that governments are ready to rise to the financing for development challenge'. Ban Ki-moon said: "We must make this year one of unprecedented progress for the poorest of the poor, so that we can realise a better, more prosperous future for all."