The truth is that since the end of WW2 Britain has almost always been had a budgetary deficit. Even in the 50s when we "never had it so good". There has only been four short periods since the of WW2 when Britain wasn't in deficit. Three of them occurred under Labour governments. Only once since the end of WW2 has there been no deficit under a Tory government - despite the fact that the Tories have been power most of that time.
The truth is that the Tories have never worried about deficit before - even when they peaked under them.
The truth is that deficits are an automatic consequence of recessions, as the graph below shows, and the world has just experienced the worst global recession since the 1930s. If it didn't feel like the worst global recession since the 1930s, then it is only because of the actions which the previous government took.

The truth is that countries which spend their way out of economic crises deal with their deficit quicker and better. Getting people back to work is the answer.
This is precisely what Argentina did when almost 10 years ago it was so much in debt (due to neo-liberal policies) that it was responsible for the largest sovereign debt default in history. They spent their way out of the crises.
For many years now Argentina has had one of the fastest growing economies in the world. Last year its economy grew by 9.2%, compare that with the shit we're in.
Argentina’s primary budget surplus widened by 19 percent in February
Argentine President says, "It’s time to end the myth of the free market"
This government's cuts have nothing to do with wanting to clear the deficit, and everything to do with a pathological and idealogical hatred of welfare provisions and public services.
The global crises caused by their mates the wealthy and powerful bankers, has given them a golden opportunity which they are determined not to miss. As things go wrong, which undoubtedly they will, they will blame everything on the last Labour government. But they will have achieved their aim, and those who matter will have remained very wealthy and privileged. They will almost certainly get away with it.
Sucker Britannia