Following the recent party conferences when Ed Miliband grabbed the headlines with his populist and popular plan for a 20-month freeze on energy prices, Labour chiefs would have expected to have built up a healthy lead; through October thus far the lead had been six points and in September one snapshot gave Labour an 11-point advantage.
But a new Ipsos MORI snapshot shows Labour and the Tories are now neck and neck on 35%; the former down two points, the latter up one. Both Ukip and the Liberal Democrats have also lost one point to place them on 10% and 9% respectively.
The last time the Conservatives posted a lead over Labour was early 2012.
The latest poll also shows Mr Miliband's personal ratings have improved since September, when the parties stood at 37% to 34%. The proportion satisfied with his performance rose from 24% to 36%. Those satisfied with David Cameron's performance is 39%, with Nick Clegg's 31% and with Nigel Farage 33%.
Gideon Skinner, head of political research at Ipsos MORI, said: "The dividing lines between the leaders are a bit clearer after conference season and they have all shored up their support, especially Ed Miliband, who has given more confidence to his own supporters.
"At the same time, we have seen the Conservatives' vote share rise in recent months in line with economic optimism. The public's view is fascinatingly poised," he added.