After the emergency budget, the main political parties have started to talk more frankly about how to plug the hole in the public finances. But although the coalition has announced plans for more ambitious cuts than first envisaged, it's remained coy about the all-important details of where the axe will fall in government departments. The Opposition attacks the new approach, although it too remains reluctant about identifying exactly where substantial savings can be made. Going where the politicians seem to fear to tread, Michael Blastland asks some of the UK's most influential policy experts and politicians how the difficult decisions on what to cut should be reached. He demands hard data on which activities should be curbed or abandoned altogether and how the sums will match the rhetoric. Michael Blastland is the author of "The Tiger That Isn't: Seeing Through a World of Numbers". Producer: Simon Coates Editor: Innes Bowen.