He fulminates on the subject of Zambia's foreign debt and how the original sum has been repaid many times over and yet - thanks to the dubious miracle of compound interest - the country owes more now than ever before. Every child born here emerges into the world with a debt of $950 (pounds 590) around his or her neck - the highest per capita debt anywhere in the world. More than that, he says, the Western nations, which take $3 in debt repayments for every $1 they give in aid, are the same countries who have taken Zambia's copper for years at unfair prices. Yet when I ask if I may get my notebook and interview him, the Catholic prelate comes over all discreet.
Church leaders in Zambia have a delicate line to tread. Their commentaries on the economic and political life of the nation - and their impact on the most vulnerable citizens - are not universally appreciated.
"Stop hiding behind God!" roared the Zambian Finance Minister recently, demanding that the Church should declare itself as a political party and stand for election against the government. It was a measure of how - in a country where the political opposition is largely ineffective - it is the Church which is the most powerful advocate for the vulnerable.
Five years ago it published a prophetic document Hear the Cry of the Poor which insisted economic policies must be judged against basic questions about human dignity. It set up a project, funded from Britain by the Catholic aid agency Cafod, to monitor the impact on the very poor of the economic reforms - with their cuts in food, health and education budgets - put in place to enable Zambia to pay the interests on its debt.
Its strength lies in the fact that its Justice and Peace secretariat is rooted in a network of information-gathering activists drawn from ordinary church members throughout the vast areas covered by its nine dioceses. They tour the villages collecting data on how much each family has eaten and spent - and on what - each month.
Added to that are the economic skills of a team led by an American Jesuit, Fr Peter Henriot, which has produced an appraisal which does not deny that reform is necessary, but insists the cost should not be borne disproportionately by the poor.
"The Church has played an absolutely crucial role in keeping the government on its toes," one senior civil servant in the Finance Ministry told me privately. It has also provided the economic data which has allowed Henry Northover, Cafod's policy analyst, to come up with a formula - now gaining support from other aid agencies - for economic reform which requires that a certain amount be spent on health and education before calculations are made on what level of debt repayments the country can afford.
What is being built by the Church and other non-governmental organisations and an intrepid free press is the beginnings of that civil society which is vital to underpin true democracy.
Life and death decisions on debt should not be left solely in the hands of Western financiers and African elites. Mechanisms are being created by which policy can be influenced by the people whose lives and deaths are at stake. Western politicians should back the process.
Tomorrow: Meeting the money men