A new poll finds that over half of voters express doubts that either President Obama or Mitt Romney can boost the economy after the election, a troubling sign for both campaigns, which have made economic policy a centerpiece of their messaging.

Six in 10 likely voters surveyed in a new Associated Press-Gfk poll released Monday gave answers ranging from "slim” to “none" when asked what effect the presidential election winner would have on the unemployment rate, according to an AP report on the poll.

The results show that two-thirds of those surveyed describe the economy as weak, and 31 percent expect unemployment to worsen this year.

Fifty-five percent say the winner in November will have "just some impact" to "no impact" on tackling the nation's budget deficits. 

The poll's results come on the heels of surveys last week showing GOP nominee Romney closing the gap on Obama by focusing on the economy. A Pew Research poll showed Obama up 4 points, with the support of 50 percent of registered voters to Romney's 46. An AP-GfK poll showed Romney trailing Obama 44 percent to 47, a gap within that poll's margin of error.

Both of those surveys and a Bloomberg National Poll showed Obama still vulnerable on economic issues.

But the new AP-GfK survey suggests skepticism over Romney’s economic policies as well.

The former Massachusetts governor’s campaign has worked to turn the election into a referendum on the White House's economic record.

Obama's team has hit back, acknowledging that while there is still work to do on the recovery, the private sector has shown improvement and the administration needs more time to correct Bush-era problems. 

Of those surveyed in Monday’s AP-GfK poll who doubt the November winner can improve economic conditions, only one in three, 32 percent, expect the economy to improve over the coming year. 

GOP voters, however, are more optimistic that the winner of the presidential election can turn the economic recovery around. Fifty-eight percent of Republicans surveyed said the election result would affect the overall economy, but fewer than half believed it would affect job growth in particular.

The AP-Gfk poll was conducted from June 14 to 18 and has a 4-point margin of error.