There is an area of public spending nearly double what Britain spends on defence, more than policing borders or our streets. It's servicing the costs of what Britain has borrowed in the past. The growing debt bomb is continuing to climb with real consequences for the taxpayer. Michael Simmons takes a look at the data and speaks to the economist Paul Johnson about what political measures the government will have to take to tackle Britain's debt crisis, what it means for the taxpayer and why the reviving modern monetary theory movement is nonsense.