LONDON — U.K. Prime Minister David Cameron said he’s not worried his Conservative Party is trailing in opinion polls and that voters will take a view in the May 2015 election on whether his economic policies have been a success.

“This year for me is a year about governing, it’s about delivering, it’s about putting in place the elements of that long-term plan,” Cameron said in an interview on BBC television’s “Andrew Marr Show” today.

“I’m content that the public will judge me and the government I run and the party I run in 2015.”

The opposition Labor Party has led the Tories in the polls by about 6 percentage points for the past six months, according to an average compiled by the U.K. Polling Report website. Cameron’s been unable to eat into that even though economic growth has accelerated and unemployment has dropped, as Labor leader Ed Miliband has focused on policy initiatives to tackle rising energy and transport prices.

A poll published last night found that 37 percent of voters who backed the Tories in the 2010 election no longer support the party, and half of them had defected to the anti-European Union U.K. Independence Party. That’s in spite of the fact that Cameron still outpolls Miliband on personal approval and economic management, according to the survey commissioned by Conservative upper-house lawmaker Michael Ashcroft.

“It is far from impossible for the Tories to win outright” in 2015, Ashcroft, who regularly conducts in-depth political polling, said in a statement. “But to do so they will need the votes of everyone who supported them last time, plus practically everyone who is even prepared to think about doing so next time.”

Cameron argued that while the U.K. economy is growing, “the job isn’t even halfway done,” as his government presses ahead with plans to cap welfare spending. He argued that it would be irresponsible for voters to return economic management to Labor, which left the U.K. with a record budget deficit before losing the 2010 election.

“It would be like handing back the keys to the people who crashed the car in the first place,” he told the BBC. “They’ve learnt nothing about the absolute mess they made of the economy when they were in power.”

In his end-of-year statement to lawmakers last month, Chancellor of the Exchequer George Osborne announced that the Office for Budget Responsibility had raised its forecast for economic growth next year to 2.4 percent from 1.8 percent and that government borrowing would be less than previously predicted.

Cameron pledged today that if the Conservatives are re- elected in 2015, pensions for the elderly will continue to rise by at least 2.5 percent a year, or in line with inflation or wages if higher.