I think frikadela and the others pointing out that Cameron/Osborne have borrowed more than Blair/Brown are missing the same point that the Labour party as a whole has missed and why the sting of not being able to manage the economy still hits - the public view borrowing differently in different stages of the economic cycle.
Cameron/Osborne were facing a recession, the income for government in tax was greatly reduced, while at the same time, there was more need to spend, most people view it as sensible to borrow in an economic downturn to keep things going - however Blair/Brown oversaw a very long boom, they had a booming economy and a relatively high government 'income' from tax. There was money in the economy, they spent it all and then borrowed more to meet additional spending they wanted to make, rather than tax higher.
And yes, many people liked the good things the Labour government was doing with all that money, and yes, liked that all those goodies arrived without the need for higher taxes, and no, they didn't look all that carefully about where it was coming from - but the Labour party's response to "why were you borrowing in a boom?" has been "It's not that bad, the Tories have borrowed more in a recession!" - it makes them look like they can't manage the economy, and they don't get that you should be behaving differently in a downturn than in a boom.
Borrowing in an economic downturn = not great but understandable/acceptable
Borrowing in a booming economy = reckless and a sign you can't be trusted to make sensible decisions with the economy
Until Labour address this - either by justifying why they borrowed in a boom or admit it was bad management of the economy, then they won't win over voters for whom a stable, well managed economy is more important than other issues like the levels of disability benefits and the hoops you have to jump through to get them.