Peter Kellner suggests Cameron may be in trouble as Ed Miliband's ratings improve significantly

Six months ago I analysed Ed Miliband’s performance. I showed how his ratings were similar to those of past opposition leaders who failed to become Prime Minister. He hoped to repeat the electoral achievements of Margaret Thatcher and Tony Blair. In fact, his figures resembled those of Michael Foot, Neil Kinnock, William Hague and Iain Duncan Smith.

Things do not look so clear-cut today. In January, Miliband’s ratings lagged far behind David Cameron’s. Now, they are similar. Indeed, YouGov’s latest poll for the Sunday Times shows Miliband slightly ahead, with his best ratings since last summer. Here is how the two men’s satisfaction ratings have moved since mid-January:

% saying they are doing… Well

Badly Net score January 19-20 Cameron 45 48 -3 Miliband 18 71 -53

July 12-13 Cameron 35 60 -25 Miliband 34 55 -21

Change Cameron -10 +12 -22 Miliband +16 -16 +32

So, is the next election in the bag for Labour? Of course not.

Miliband’s ratings may have improved, but they are still negative. When people are asked who would make the best prime Minister, Cameron still enjoys a clear lead – though this has declined from more than 20 points in January to 10 points today. And Labour’s voting-intention lead, 9 points in our latest survey, is below par for opposition parties in mid-term.

However, it is plain that public opinion has moved significantly during the past six months.

Last winter Miliband looked like a near-certain loser. Since then the chances of him becoming Prime Minister at the next election have improved significantly.

Hang about (I can hear some readers saying), surely Miliband’s fundamental weaknesses are still there. Doesn’t he still look like a boy in a man’s world? Doesn’t he need more gravitas to look like a Prime Minister in waiting? Doesn’t he lack the respect of Britain’s voters?

My answer is not that his reputation has been totally transformed, but that it is on the move – while, at the same time, Cameron’s reputation has taken a series of severe blows. In as far as the contest at the next election will involve a comparison between the two party leaders, Miliband may no longer be at a disadvantage.

More detailed YouGov tracking data show what is happening. Every fortnight we ask respondents to look through a list of eight attributes, and to pick out all those that apply to each of the main party leaders. Here are the figures for four of the key attributes:

Cameron %

Miliband % Cameron lead January 29-30 Sticks to what he believes in 30 13 17 Decisive 24 6 18 Strong 21 4 20 In touch with ordinary people 9 19 -10

July 8-9 Sticks to what he believes in 17 17 0 Decisive 13 9 4 Strong 15 7 8 In touch with ordinary people 6 25 -19

Cameron’s scores are all down, while Miliband’s are all up. On the three attributes where Cameron held strong leads in January, those leads have either disappeared or been sharply reduced; on being in touch with ordinary people, Miliband’s lead has almost doubled.

That said, Miliband still has some way to go. He can’t be happy that only fewer than 10% pick out strength or decisiveness as definite attributes. These figures will have to rise sharply if Labour is to become favourite to win the next election.

But Miliband has almost three more years to persuade voters that he has what it takes to run Britain, and the momentum is currently with him.

Meanwhile, Cameron is in trouble. Three months ago, the dip in his ratings could be explained as the short-term price he and his party paid for a botched Budget. But his problems, headlines and poor ratings have continued. His mid-term blues are beginning to look worryingly persistent.

Of course, like Miliband, Cameron has almost three years to put things right. If Britain’s economy is recovering strongly by 2015, the Conservatives should do well. At the moment, however, the next election looks wide open.

Until recently, and despite the continuing recession, I thought the Tories the likely winners. I don’t think that any longer.

See the survey details and full results of our latest Sunday Times poll