The pair are believed to have clashed over opposing ideological visions for Mr Trump's White House.
“[Steve] recently vented to us about Jared being a ‘globalist’ and a ‘cuck'," an official who did not wish to be named, told The Daily Beast website. "He actually said ‘cuck,’ as in “cuckservative.’”
“Cuckservative,” a portmanteau of “cuckold” and “conservative,” has become a popular insult on the right and is used as a sexually and racially charged version of “RINO,” an acronym for “Republican In Name Only.” On its own the word cuckold means a man whose wife has cheated on him, and was used frequently by William Shakespeare.
“Globalist” is a term frequently used by nationalist, pro-Trump right-wingers to attack political opponents but the term has been criticised for carrying anti-Semitic undertones. Mr Kushner is Jewish.
The official added: “There is a big fight going on. It’s all about policy. There’s tension on trade, health care, immigration, taxes, terrorism, you name it.”
Another official reportedly said that Mr Bannon “thinks Jared is worse than a Democrat… Steve has a very specific vision for what he believes, and what he shares with Trump. And he has for a long time now seen (Mr Kushner) as a major obstacle to achieving that.”
Outlets including The New York Times reported that Mr Bannon has considered resigning from the Trump team altogether following the failure of two key policies he is believed to have orchestrated – the travel ban against seven Muslim-majority nations and the repeal and replacement of Obamacare.
Mr Bannon is reported to have said he “loves a gunfight” when asked about his relationship with Mr Kushner, according to Axios.Reuse content