Presented by John Humphrys and Edward Stourton. Margaret Eaton of the LGA and Paul Kelly of Asda discuss if supermarkets should pay towards the collection of their packaging as an incentive to cut back on using so much of it. Author and photographer Nic Dunlop explains the story behind the Cambodian leader responsible for 'the worst mass murders in history'. Niall Dickson, chief executive of the King's Fund, discusses if the government's dementia strategy is working well enough. Correspondent Peter Bowes explains Roman Polanski's efforts to get the criminal case which has kept him out of the US for more than 30 years dismissed by the courts. Dr Christophe Fournier of the MSF and Moeletsi Mbeki, deputy chairman of the South African Institute of International Affairs, discuss the humanitarian crisis in Zimbabwe. Economics editor Stephanie Flanders explains the importance of the Baltic Dry index. Vice-Admiral Sir Tim McClement discusses how two nuclear-armed submarines (one British and one French) collided in the Atlantic Ocean. Thought for the day with columnist and novelist Anne Atkins. Shadow Secretary of State for Communities and Local Government Caroline Spelman discusses proposals to give more power to councils. Former ITN newsreader John Suchet speaks about his wife's Alzheimer's and Imelda Redmond of Carers UK discusses what more can be done to help those caring for dementia sufferers. Poet Laureate Andrew Motion and Professor John Mullan discuss if students understand the Bible and classical mythology. The Conservatives will publish proposals on how they would allow local councils to operate. Local government minister John Healey responds to the plan. Dr Chris Lintott, an astrophysicist at Oxford University, explains why they have been running a project asking the public to help discover more about our universe. Professor David Cesarani and Holocaust survivor Freddie Knoller discuss France's role in persecuting Jews. Economists Steven Bell and Liam Halligan discuss the latest figures for the rate of inflation. Correspondent Roland Buerk discusses the promise from Secretary of State Hillary Clinton that the US will offer North Korea aid if it completely eliminates its nuclear programme. Officials have banned kissing at parts of Warrington Bank Quay railway station, saying it holds up departing taxis. Ken Gibbs of Virgin Trains explains the decision.