Over a year and a half into Barack Obama's Presidency, an increasing number of Americans — nearly one in five — incorrectly believe that he is a Muslim, a new survey has revealed. The view that Obama is a Muslim is more widespread among his political opponents than among his backers, the Pew Research Center said after releasing the results of its national survey. The Pew Research Center said 18 per cent of the Americans now say Obama is a Muslim, which is up from 11 per cent in March 2009. Only about one-third of the adults (34 per cent) say Mr Obama is a Christian, down sharply from 48 per cent in 2009. The survey was completed in early August, before Obama's recent comments that appeared favouring the proposed construction of a mosque near the site of the former World Trade Center, the Center said. White House faith advisor attributed this to the misinformation campaign by his opponents. "While the President has been diligent and personally committed to his own Christian faith, there is certainly folks who are intent on spreading falsehood about the President and his values and beliefs," said Joshua DuBois, the White House faith advisor. The belief that Mr Obama is a Muslim has increased most sharply among Republicans, especially conservative Republicans, while the number of independents who say Mr Obama is a Muslim has also increased significantly. However, there has been little change in the number of Democrats who say Mr Obama is a Muslim, Mr Pew said.