"The G8 have a credibility problem. If you quantify what has been delivered, you will find very little," he says. While praising nearly all of them for more than halving Zambia's $6 billion external debt, he warns that the debt relief process is taking too long, leading the country to spend hundreds of millions each year on interest repayments.
Many Zambians question why the richest countries took nine months to write off Iraq's debt totally, he says, yet, on Africa, they have been talking about writing off debt for decades.
Even if poorer countries' debts were cancelled and trade barriers reduced, he argues, they would still struggle because they would need loans to build up their infrastructure. "The EU is giving poor European countries grants, but when it comes to Africa they don't give a damn."
At the same time, subsidies for European and American products make African exports to these countries uncompetitive.
Mr Patel says Africans appreciated the work of the UK as a "confirmed cheerleader". "It's good to have among the G8 a leading member pushing the Africa agenda because we don't have the capacity nor the lobbying skills and resources to get G8 to pay attention to it." But he hopes the UK and G8's other European members can swiftly end their disagreements with the US over what action is needed, including which methods to use for writing-off the International Monetary Fund's loans.
The rows remind him of a traditional African saying: "When two elephants fight, it's the grass that suffers."
TRADE * Between 1997 and 2001 commodities lost more than half their purchasing power compared to manufactured goods so poor countries had to export twice as much to purchase the same amount of imports.
* The G8 nations maintain tariff barriers or taxes of up to 900 per cent on key third world agricultural exports such as sugar, rice and dairy products. By contrast many poor countries have had to reduce tariff barriers to imports as a condition of IMF or World Bank loans.
* Europe subsidises sugar beet by 300%. US subsidises cotton by 100%. Sugar and cotton, along with coffee, account for 50% of Africa's agricultural exports. Farmers in Burkina Faso produce a pound of cotton for 21 cents compared to 73 cents in the US. Removal of EU and US cotton support would increase African cotton exports by 75%.
* The developing world spends $13 on debt repayment for every $1 it receives in grants.
* Seven million children die each year as a result of the debt crisis through money diverted from healthcare, nutrition and clean water. This is 25 times the number estimated to have died in the 2004 Asian tsunami.
* If the G8 countries gave effective debt relief to the 20 poorest countries, it would cost $5.5 billion - equivalent to the building costs of Eurodisney in Paris.
* The $350bn a year that G8 countries and Australia spend on subsidising their farmers is seven times what they donate to poor countries in aid. The money is enough to guarantee clean water for everyone in the world ($170bn), a primary education for every child not in school ($6bn), basic health and nutrition for all ($13bn) and pay off the public debt of the most indebted countries in the world ($90bn).
* The Commission for Africa is demanding $25bn more aid per year for the world's poorest continent. That is the equivalent of half a stick of chewing gum for each person in the G8 countries.
* 40 million die from hunger and hunger related diseases each year - equivalent to 300 jumbo jets crashing each day with no survivors. Half the victims are children.
* Three billion people, or half the world's population, lives on less than $2 a day. That means that all their food, clothing, shelter, books, travel to school must be covered with a mere $1to $2 per day.
* And the poverty gap is growing: in 1950, income in G8 countries was 35 times that of poor countries; by 1973 it was 44 times; and by 1994 it was 74 times.
* The ten hottest years on record have occurred since 1991. Sea levels are rising and are forecast to rise another 88cm by 2100, threatening 100 million people in low-lying areas. During the 20th century, world energy use multiplied ten times. It is expected to double again by 2050.
* The G8 countries account for more than 65% of global GDP and 47% of global carbon dioxide emissions.
* 150,000 sq km of rainforest - an area the size of England and Wales - is destroyed every year. Deforestation contributes 30% of all carbon dioxide emissions through slash-and-burn activities.