President Barack Obama’s approval rating has climbed to 50 percent and a majority of voters for the first time favor Obama over former Massachusetts Governor Mitt Romney, according to a Washington Post/ABC News poll.

The poll, conducted last week and released today, showed that, in a head-to-head contest, Obama leads Romney, the current front-runner for the Republican nomination, 51-45 percent among registered voters and 52-43 percent among all Americans.

The results of the head-to-head match-up were a reversal of last month’s Post/ABC poll, which gave Romney a two percentage point lead over Obama, 48-46 percent, among registered voters and a one percentage point lead, 47-46 percent, among all Americans.

Obama’s approval rating was the highest since the killing of Osama bin Laden in early May. Nearly as many Americans surveyed — 46 percent — disapprove as approve of the president’s performance in office, the poll found. Among registered voters, 49 percent said Obama deserves a second term and 49 percent said he didn’t.

Among political independents, who may determine the outcome of the Nov. 6 election, 47 percent approve and 50 percent disapprove of the way Obama is handling his job, according to the poll. His approval rating among independents has climbed from a low of 34 percent in the fall and is up from 37 percent a month ago.

The telephone poll conducted Feb. 1-4 among a random national sample of 1,000 adults has a margin of error of plus or minus four percentage points.