Biggus, I'm sorry I didn't see your post.
The coalition's policy from 2010 was always to
eliminate the budget deficit by 2014/15, which has now been pushed to 2015/16
BBC News - UK economy: Deficit
However, even if they had achieved that, then over 5 years the national debt would have gone up by say £160Bn + £130Bn + £110Bn + £95Bn + £80 Bn
This again, isn't true I'm afraid, the original plan was always to have national debt falling after 2013/14, which like the deficit elimination, has been pushed back by a year. It is possible to have a deficit and see debt falling in the short run, so long as government bonds reaching maturity are cumulatively worth more than the deficit.
Admittadly, I got overzealous in claiming that the government would half the national debt by 2015, but you'll find that as soon as a surplus is reached, debt can fall very rapidly yada yada yada