Republican White House hopeful Mitt Romney is losing favor among US voters just three months ahead of his tough election battle with President Barack Obama, a new poll showed Wednesday. The Washington Post-ABC News poll showed that 49 percent of voters have a negative view of the former Massachusetts governor, up from 45 percent in May. Forty percent of voters, meanwhile, see him in a positive light, practically the same proportion from the spring. In contrast, 53 percent of voters said they had a favorable opinion of challenger Obama, while 43 percent said they felt negatively about him. By a margin of 53 percent to 40 percent, more key independent voters see Obama favorably rather than unfavorably. Fifty percent of this group view Romney unfavorably, compared to 37 percent who consider him favorably. Romney has has a rough summer marred in part by a series of slip-ups during a trip abroad to Britain, Israel and Poland. He has also come under fire over his unwillingness to release his tax returns from before 2010. Among supporters of his own Republican Party, 83 percent have a good feeling about Romney but just 41 percent feel “strongly favorable.” Sixty-one percent of Democrats meanwhile feel this way about their candidate. The poll, carried out between Aug. 1 and Aug. 5 surveyed 1,026 adults. The margin of sampling error was plus or minus four percentage points. A separate Quinnipiac University/New York Times/CBS News poll shows a tight race shaping up in the swing states of Wisconsin, Virginia and Colorado. While Romney leads Obama 50 percent to 45 percent in Colorado, the president holds a lead over his rival in Virginia and Wisconsin.