People seem to be forgetting a few points when predicting a Tory majority.
1. They couldn't secure one in 2010 when people had nothing to judge Cameron and Osbourne on and when Labour were being blamed for everything and had Brown as leader. They should have had a landslide but failed to get one.
2. UKIP are not going away and neither is European question
3. This government is wreaking the NHS - that alone is vote winner for any opposition
4. The economy is a mess and the its "all Labour's fault" is rapidly running out of steam to the extent people are, I believe, sick of hearing it. They aren't that interested in who's fault it was but why it hasn't been fixed.
5. That have not managed to gerrymander the election by getting the number of constituencies reduced
6. A lot of people are being affected directly in a negative way with kids having to pay tuition fees of £9K or losing housing benefit/tax credits.
7. Back to the economy, its just not going to pick up that much if at all between now and the election so they won't have much success to point to.
What Labour has to do other than relying on all the above negatives about this government is come up with an effective way of mitigating Tory spin. It's been apparent from day 1 that they have a tactic of telling lies often enough so people will believe it. The way in which any discussion on the economy is always predicated by "Clearing up labours mess" is a case in point.