This has been done to death, but once more won't hurt i suppose. The last three polls show, 6 months before the election:
YG
CON 31
LAB 37
LD 7
UKIP 15
LA
LAB 33%
CON 27%
LDEM 9%,
UKIP 17%
POPULUS:
LAB 37%,
CON 33%
LDEM 9%
UKIP 12%
All shows strong leads for labour that would lead to medium-large majorities on fairly crude uniform national swing models. That is without taking into effect the Tory seats that UKIP are going to cost the tories (estimates go from 15-40ish) or the fact that, due to the way the vote is distributed geographically and other factors, the tories need to win 40% of the vote and for labour to drop to high 20s/v low 30s and to lose all the lib-dem switchers in the process to stop them getting a majority.
As for Miliband, he's had pretty bad personal ratings since being elected (and he keeps managing to win various elections over many years despite this impassable handicap doesn't he?) but they haven't effected the polling for the parties on voting intention.