Why has Gordon Brown been such a disaster as PM? LAUREN HEALY, Lancaster
You are asking the wrong guy. I am only in government because of Gordon. I knew him during my years at the UN and the World Bank as one of the world's most internationally-minded finance ministers. As Prime Minister, he has stuck to that agenda.
You've advised plenty of foreign governments in a crisis at the polls. How would you advise this one? CARL FAIRRIS, London
Keep our nerve. Having run polls all over the world, I have learnt one graph usually matters as much as any poll: what's happening to the economy. This government's falling poll numbers have tracked an international economic downturn.
We need to work our way through this, showing competence and fairness, so that voters see daylight by the time the election comes
How long were you a Labour supporter before you joined the Government? BEN OLIVER, Harrogate
At my rather conservative boys' prep school I ran as the Labour candidate in the 1966 mock election. Later, I had a spell as an active SDP member before 21 years abroad, when I was not a member of any party.
Do you despair of Mugabe? Can we do anything concrete? ANNA MORLEY, Bristol
Mugabe has presided over an economic and humanitarian disaster in a country that should be an economic leader in the region. I hope the deal between MDC and Zanu-PF may offer a way forward. But Mugabe does not have any track record of being a reliable partner.
What knowledge did growing up in Zimbabwe give you that you bring to bear on your dealings with the country now? CHARLIE BARNES, Kidderminster
I was actually born and brought up in the UK. My father was a South African. My first real experience of Zimbabwe was as a young reporter who helped break the story of British companies' sanctions-busting to support the white Smith regime.
Do you agree that the amount of aid wasted by African regimes is scandalous, and that Western aid is just money shovelled into a quicksand? NAOMI WITHE, Peterborough
Corruption remains a major problem in Africa, which is why the UK monitors its aid so carefully. But aid does work. Many African economies have been growing at impressive rates in recent years. In the last decade, the UK has given seven million Africans access to clean water, provided millions of bed nets to protect against malaria and helped millions of children complete primary education.
Do you think aid agencies fuel negative stereotypes of Africa with their constant scaremongering and fund-raising? JULIE LESTER, Leeds
Aid agencies, often working with the UK Government, make a real difference by getting aid to poor people and they rightly work hard to draw attention to problems. It's unfortunate that bad news often gets more coverage, but Africa is a hugely diverse continent, where the good news doesn't get as much attention as it deserves.
Is the UN broken? If it is, what can be done to fix it? LIONEL TIMMS, Cardiff
The UN's strengths are also partly its weakness. Any organisation with 192 members will struggle to agree on everything. But its strength is in providing a voice for every country, and a forum to resolve global problems. And it does vitally important work. For instance, the UN has 100,000 peacekeepers around the world. The WFP is delivering critical supplies to people in desperate need. The WHO eradicated polio and is working to do the same to other deadly diseases.
But as with any large organisation, it needs to review and renew itself. That means creating a more representative Security Council, making its overseas operations more streamlined, and designing and using the tools to prevent, resolve and recover from conflict.
How can the UN continue when it is so despised by so many in America? WILLIAM HERBERT, Stevenage
The UN does need to up its game, for instance to cut wasteful mismanagement and deliver well-trained peacekeepers. But the UN has many supporters in the US, who recognise the vital work it does.
You were a defender of the oil-for-food programme when you worked at the UN. Would you still defend it? LAURA RUSSELL, Wolverhampton
The idea behind oil-for-food was right. It attempted to minimise the impact on ordinary Iraqis of the sanctions that were targeted at Saddam Hussein's regime. I always said that there were failings, which mainly resulted from Saddam's attempts to subvert the programme. The UN's failures were largely managerial. The independent inquiry found that most of the criminal activity involved companies and politicians seeking favour from Saddam. Heads have rolled in the US, Australia, India, France and elsewhere, not just at the UN.
Do you still believe there should be an EU seat on the UN Security Council? RHONA PEEL, Manchester
I never did, although I do believe that the UNSC should be more representative. But there's no provision in the UN charter for a seat on the Security Council. I was talking of EU representation on the boards of UN development and humanitarian organisations, where it is a major donor.
Are you hopeful about the new Pakistani President, Asif Ali Zardari? ED FARLEY, Belfast
President Zardari's election takes forward Pakistan's democratic transition, which is fundamental to long-term stability, peace and prosperity. He has some big challenges, but I hope that the renewed democratic foundations, supported by committed international partners, and a fresh start for regional relations, will see Pakistan prosper.
You believe that opium production should be legalised in Afghanistan, and the crop bought for medicinal purposes. Why doesn't this happen? BRIAN NOLAN, London
I don't believe that purchasing the Afghan opium crop would provide a viable solution to poppy cultivation. Legal production requires the kind of transparent, well-regulated production where you can ensure opium is only sold for approved use. The conditions do not exist in Afghanistan, so the major risk is that legal opium would only supplement, not substitute, illegal opium production.
Do you support the legalisation of drugs? LEONARD DODD, Falkirk
Who do you want to win the US presidential election? JENNIE VERNON, via email
What I will say is that I still hope that the early expectations, that two remarkable candidates would re-ignite excitement in America at home and abroad, will be realised, and that they are able to lay out competing visions for their country and not get dragged off into negative campaigning.
Do you still think the right-wing talk show hosts are too influential in the US? DARRIN PORTER, Lincoln
I find it remarkable in the US that the Left are always complaining about the dominance of the right-wing talk show hosts, while the Right rail against a liberal media bias.
What do you think of your nickname "Mad Mark"? KELLY MONROE, Rushden
That's a new one to me.
Would you become a minister in David Cameron's government if he won the election and asked you? TARA LOWRY, Bournemouth
As a former journalist, what do you think of the media now? KEVIN BRIGGS, Milton Keynes
I hope I was much fairer but I probably wasn't!
Are the foreign politicians you meet impressed by the fact you're a Lord? KATE MAXWELL, Marlborough
Perhaps some. Most know the score and would think me more powerful if I had the initials MP after my name.Reuse content