WASHINGTON, July 31, 2008 (AFP) - Republican John McCain is gaining on White House rival Barack Obama in the pivotal swing states of Florida, Ohio and Pennsylvania, according to Quinnipiac University polls released Thursday.

The Connecticut university said Obama had seemingly gained no traction from a much-hyped foreign tour last week that was designed to flag his credentials to serve as commander-in-chief.

'The 64,000-dollar question is whether Senator John McCain's surge is a result of Senator Obama's much-publicized Middle Eastern and European trip, or just a coincidence that it occurred while Senator Obama was abroad,' said Peter Brown, assistant director of the Quinnipiac University Polling Institute.

'While Obama was on tour, trying to show voters he could handle world affairs, voters were home trying to fill their gas tanks,' he said.

In Florida, according to the survey, Obama has 46 percent to McCain's 44 percent, compared to a 47-43 edge for the Democrat in mid-June.

The numbers were the same in Ohio, 46-44 percent for Obama, from a 48-42 lead last time.

In Pennsylvania, Obama has a slightly bigger lead of 49-42 percent, compared to 52-40 percent last month.

As Quinnipiac noted, no candidate has been elected president since 1960 without taking two of these three largest swing states in the US electoral college.

At a time of sky-high fuel prices and job insecurity, voters in all three states care more about energy policy than about the Iraq war, the pollsters said.

McCain has come out in support of scrapping a federal ban on offshore oil drilling, which has been derided by Obama as a political gimmick but enjoys support from a clear majority of voters.

'McCain clearly sees public support for drilling as a means to challenge Obama's claim to be the best candidate to fix the economy,' Brown said.

'More voters still say Obama has the best energy plan. Whether that's because they don't know the specifics of each man's plan, or just don't think drilling is important enough to swing their votes, is the great unknown.

'Obama's reduced lead also may reflect the normal let-down from a big high after clinching the Democratic nomination,' he added.

The Quinnipiac University polls were conducted from July 23 to 29. The margin of error was 2.8 percent in both Florida and Ohio, and 2.7 percent in Pennsylvania.