Just how much is Ed Miliband holding back Labour?

In today's YOUGOV opinion poll they have asked the respondents Who would make the best PM? From a list of Cameron, Miliband & Clegg or choose Don't Know. Don't Know rated the highest as I am guessing some may have put Farage or for Scotland Salmond.

But the most striking thing from the results is that Labour have comfortable leads in their heartlands but those same voters do not think Miliband would make the best PM. Now defenders of this position say it means that it is great, because it means the voters are voting for the party not just the leader. So policies win out. But the leader is the person who will ultimately decide which policies to run with, how to implement those policies and if most of his own supporters don't think he is the best man for the job. Well, what does that say for his future as PM? If people don't rate him now, how will they rate him when he has had to make unpopular decisions?

Anyways, here is some of the breakdowns.

Your thoughts are welcome.

Yougov Who would make the best PM? David Cameron 35% +1 Ed Miliband 21% +2 Nick Clegg 4% -1 Don't know 40% -2
— General Election (@UKELECTIONS2015) June 5, 2014

Yougov North of England LAB 43% CON 29% UKIP 15% GRN 7% LD 5% Who would make best PM? Cameron 33% Miliband 24% Clegg 3% DK 40%
— General Election (@UKELECTIONS2015) June 5, 2014

Yougov London LAB 42% CON 34% UKIP 11% LD 10% GRN 2% SNP 1% ??? Who would make the best PM? Cameron 38% Miliband 22% Clegg 3% DK 36%
— General Election (@UKELECTIONS2015) June 5, 2014

Yougov Southern England CON 37% LAB 30% UKIP 15% LD 10% GRN 7% SNP 1% ??? Who'd make best PM? Cameron 40% Miliband 18% Clegg 5% DK 38%
— General Election (@UKELECTIONS2015) June 5, 2014

Yougov Mids/Wales CON 37% LAB 36% UKIP 12% LD 5% GRN 4% PC 4% Who would make best PM? Cameron 35% Miliband 21% Clegg 3% DK 41%
— General Election (@UKELECTIONS2015) June 5, 2014

Yougov Scotland LAB 46% SNP 29% CON 11% LD 6% UKIP 5% GRN 3% Who would make best PM? Miliband 25% Cameron 18% Clegg 4% DK 53%
— General Election (@UKELECTIONS2015) June 5, 2014

http://cdn.yougov.com/cumulus_uploads/document/f2ztyz9kmu/YG-Archive-Pol-Sun-results-040614.pdf