Two polls put the Conservatives ahead of Labour on Monday, giving the right-leaning party an unexpected morale boost before European elections later this month and a national election next year.
The surveys are likely to cause unease in Labour's ranks about its election strategy as the same polls show that Ed Miliband, the party's leader, is struggling to score well when it comes to voter approval despite being credited with coming up with some popular policies.
One poll, carried out last week, put Conservative support at 34 percent, 2 percentage points ahead of Labour, who have enjoyed a lead of up to 10 percentage points since March 2012, the last time the Conservatives topped a similar poll.
The survey, based on a phone poll of 1,001 adults, was funded by Michael Ashcroft, a Conservative peer and a former deputy chairman of Cameron's party. A long-time funder of such polls, he said in a statement that his polling was apolitical and pointed out "uncomfortable truths" to all parties.
A second poll, from Guardian/ICM, put the Conservatives on 33 percent, 2 percentage points ahead of Labour whose support it showed had fallen by 6 percent since April.
It was based on responses from a random sample of 1,000 adults. The left-leaning Guardian newspaper, which published the results, said it showed that support for the Labour party was draining away.
Despite the Conservatives' new slim poll lead, experts said that Britain's voting system meant the results would still mean that Labour would win a few more parliamentary seats than Cameron's party if an election was held today.
The Conservatives will have to increase their support still further if they are to win more seats that Labour, they said.
The polls come at a time when the British economy has exited a prolonged recession and begun to grow at a clip which means it is likely to expand faster than any other Group of Seven economy this year.
The last time the Conservatives enjoyed a lead in a national opinion poll was in a March 2012 Guardian/ICM survey which put them on 39 percent against Labour's 36 percent.
Despite the polls, the outlook for Cameron's Conservatives in elections to the European Parliament later this month is mixed with most opinion polls showing it will be beaten into third place behind Labour and the anti-EU UK Independence Party (UKIP).