Today's Times leads on a striking new poll showing Labour surging to a four-point lead following Ed Miliband's appearance in his (non) debate with David Cameron this week.

If borne out on May 7th, this means Labour would be the largest party in Parliament with Miliband as prime minister.

The poll has led to panic among Tory MPs who for months have been confidently predicting they will soon "crossover" in the polls, leading to Cameron's comfortable return to Downing Street.

Today's Times quotes two Tories in marginal seats, who criticise Cameron for a series of "unforced errors" during the campaign and a failure to "deliver the lift in the national polls that we need".

Labour meanwhile, are this morning elated that their leader appears to have given their campaign such a significant boost.

Neither side should get too carried away however. This is just one poll and with a margin of error of +/- three per cent, the race could actually be much closer than YouGov suggest. Indeed one other poll out today in the Observer suggests the parties are still neck and neck.

However if you dig deeper into today's YouGov poll there are two even more encouraging signs for Ed Miliband and Labour.

1. Labour has a big lead among those who saw the Sky/Channel Four (non) debate.

Among those who watched the whole programme, Labour has a ten point lead according to YouGov. They also have a five-point lead among those who only saw clips or reports about it. Overall, among those who saw at least some of the debate, 49% said Miliband came across better, with just 34% saying Cameron. This is a stunning finding given how much better the prime minister's ratings are than Miliband's.

This shows exactly why Cameron and his advisers have been so keen to avoid head-to-head debates with the Labour leader and why Labour have done everything they can to pressure Cameron into accepting them. Central to the Tory election campaign is the idea that Miliband is simply unelectable as prime minister. Before this week, this was a very easy argument for the Tories to make. Miliband's strong performance on Thursday has made that argument very much harder. With at least one leader's debate still to happen, things are not looking good for the Tories.



2. Miliband's personal ratings have improved massively.

At the end of last month Ed Miliband had net personal ratings of -46% according to YouGov with 68% of voters saying he is "doing badly" as leader of the Labour party. Today's poll for the Sunday Times shows a big boost in his ratings, which are now up to -29%.

These headline numbers are still not great. However among Labour voters Miliband has seen a big recovery. At the end of last month, 54% of Labour voters thought he was doing well and a whopping 41% thought he was doing badly. These were terrible figures and suggested that Miliband's dire ratings could be fatal to Labour's chances on the day.

However, today's poll found that almost three quarters (72%) of Labour voters now think he is doing well, as opposed to just 24% who think he is doing badly. That one-in-four Labour voters still think he is doing a bad job is not great for Miliband, especially when you compare it to Tory voters, 94% of whom say Cameron is doing a good job. However, it is a massive improvement on the situation Miliband faced just one month ago.

Other findings in the poll are even more encouraging for Labour. YouGov found that Miliband now has a lead over Cameron among voters on which party leader is 'most in touch with ordinary people's concerns', as well as being 'most genuine and authentic'.

If voter doubts about Miliband are the biggest obstacle to Labour forming the next government then that obstacle now looks much more navigable than it did just last month.

Expect a Tory fightback in the press



Having followed two election campaigns run by the Conservative campaign chief Lynton Crosby in London, I can confidently predict that Labour can now expect their leader to come under sustained attack, both from the Tories and from their many supporters in the press.

At the last mayoral election, several polls showed Ken Livingstone on course to recover City Hall from Boris Johnson. However as the campaign went on, Crosby unleashed a series of claims about Livingstone's tax affairs which totally derailed Labour's campaign. These stories were deliberately timed to disrupt Labour's momentum in the campaign and were highly effective, as I have written before. Labour can now safely expect similar treatment over the next few days and weeks.

However, with just weeks to go until polling day, the fact that Labour currently hold a clear lead, suggests that things are not going anywhere near to plan for David Cameron and the Conservative party.

If the Tories thought that Miliband and Labour would give them an easy ride back into Downing Street, today's poll suggests they were sorely mistaken.