WASHINGTON — US Republican Mitt Romney has pulled ahead of President Barack Obama for the first time in more than a month and leads 45 percent to 44 percent among likely voters, according to a Reuters/Ipsos tracking poll released Wednesday. With under four weeks until the Nov. 6 election, Obama's post-convention bounce in polls has now disappeared. Voters warmed to Romney across a range of policy issues following a strong debate performance by the Republican last week. On Tuesday, the tracking poll had the two candidates tied at 45 percent. The online survey of 1,027 likely voters was conducted between Oct. 6 and Oct 10. The precision of the poll is measured using a credibility interval, which is plus or minus 3.5 percentage points for likely voters. Romney outmaneuvered a subdued Obama in their first debate last week and has seen crowds of thousands of people turn out for him in Ohio this week. On Wednesday, the campaign became a spat over how Romney got there — and whether his hints of moving to the political center on abortion, taxes and other issues reflected a truly “Moderate Mitt” or was a conservative's sleight of hand, aimed at snaring moderate voters in a tight race for the White House. At issue was an interview in which Romney told the Des Moines Register newspaper that he had no plans for legislation to restrict abortion, one of the great dividing lines between conservatives and liberals in American politics. The statement seemed to contrast with the staunch anti-abortion stance Romney had taken this year while trying to attract conservatives' votes during the battle for the Republican nomination. Romney clarified his position on Wednesday. “I've said time and again that I'm a pro-life candidate and I'll be a pro-life president,” he told reporters. As Massachusetts governor he had supported keeping abortion legal but says he later changed his mind. Obama's campaign and abortion-rights groups pounced. They said it was the latest example of hypocrisy or truth-bending by Romney as he tries to carve into Obama's advantage among women voters and win what Reuters/Ipsos tracking polls show as a dead heat for middle-class voters. — Agencies