The wife of the imam behind the plan to build a mosque and Islamic centre in Manhattan, just by the site of the 9/11 attack, has likened opposition to the proposal to prejudice against Jews.
Daisy Khan said she was “deeply concerned” about the negative reaction to the project, known as the Cordoba Initiative.
Mrs Khan, whose husband Imam Feisal Abdul Rauf is the moderate Muslim in charge of the plan, said: "This is like a metastasised antisemitism. That's what we feel right now.
"It's not even Islamophobia, it's beyond Islamophobia - it's hate of Muslims.”
The construction of the so-called Ground Zero mosque has split America, with some labelling it as insensitive and others arguing that it is a matter of religious freedom.
President Barack Obama, New York mayor Michael Bloomberg and Sarah Palin have all weighed in to the debate. Mr Bloomberg has called for the mosque to be built, while Ms Palin is a vociferous opponent and has used Twitter to promote her views on it.
President Obama has endorsed the plan and said Muslims "have the same right to practice their religion as anyone else.” But he later said he was commenting on the right to build the mosque, not the wisdom of doing so.
Jewish groups have also been divided on the issue, with the Anti-Defamation League coming out against it and J Street organising a petition in support.
Demonstrations were held both for and against the plan in New York this weekend.
Mrs Khan stressed that the building would be “first and foremost a community centre.
"It's basically become a place where ideas can be exchanged, but tolerance, mutual respect can also be extended.”