During last week's Commons tribute to Margaret Thatcher, the Conservative MP Conor Burns, a close confidante of the former prime minister, recalled showing her a poll last November with the Tories nine points behind. Thatcher, he revealed, replied, "That's not far enough behind at this stage", explaining that "she took a view that to do things that were right did entail unpopularity until people saw that what you were doing was working."
Thatcher, then, would be alarmed by the latest polls, which show Labour's lead has fallen to its lowest level for months. The YouGov daily tracker  puts the party on seven points, down from eight the previous day (and a peak of 14  last Thursday) and the lowest Labour lead since David Cameron's EU speech in January. Yesterday's Guardian/ICM survey  made similarly grim reading for Team Miliband, with Labour's lead down to six (from eight last month) and Miliband's net approval rating down to -23, his worst since becoming leader.
It could, of course, be normal sample variation but it's plausible that the Tories, whose YouGov vote share has risen five points to 33 per cent since last week, have benefited from a Thatcher effect. Polls have shown  that most voters continue to regard her (if not all of her policies) fondly and, with politics as normal suspended, David Cameron has enjoyed largely free rein to hail her conservative values. Labour, meanwhile, has presented a divided face to the country as Tony Blair's piece  in the centenary edition  of the NS has been followed by a series of other critical interventions  from party grandees. Voters, as pollsters regularly attest, don't like divided parties, the reason why John Prescott told Monday night's PLP meeting that it was "crazy" for Labour to fracture just two weeks before the local elections.
Thatcher, incidentally, may have been right about the Tories not being far enough behind (or Labour not being far enough ahead). As the data below from YouGov's Peter Kellner  shows, no modern opposition has ever won without being at least 20 points ahead in mid-term. But with the right divided and the Lib Dem vote likely to collapse in Tory-Labour marginals, Miliband has some hope of defying this trend.
Peak poll leads