Donald Trump's Jewish son-in-law, Jared Kushner, appears set to play a pivotal role in the future administration, and as such has come under increasing pressure from those concerned about the antisemitism that stained the electoral campaign run by the president-elect.

There has been speculation that Mr Kushner, who is married to Mr Trump's daughter, Ivanka, will become an informal adviser to the president in the Oval Office.

In an interview with Forbes magazine, media tycoon Rupert Murdoch, who is close to Mr Kushner, said: "I assume he'll be in the White House throughout the entire presidency… he'll be a strong voice, maybe even the strongest after the vice president."

Among the prominent American Jewish voices accusing Mr Kushner of being willing to ignore or excuse incidents of racism and antisemitism within the Trump campaign was filmmaker Rob Reiner. He said: "I don't understand Jared Kushner at all. What is he doing? He's turning his back on his religion and his heritage just so he can make money? I don't get it."

In a "Letter to Jared", Jane Eisner, editor of America's most prominent Jewish news site, the Forward, insisted on "the absolute necessity for you to represent the concerns of American Jews to the person who will soon be president".

Speaking to Forbes last week, Mr Kushner defended his father-in-law. He said: "You can't not be a racist for 69 years, then all of a sudden become a racist, right? You can't not be an antisemite for 69 years and all of a sudden become an antisemite because you're running."

Mr Kushner added that time would show that Mr Trump would not allow "hateful rhetoric or behaviour" in his administration.

The Orthodox property dealer has played a key role in his father-in-law's attempts to display his pro-Israel credentials. The Times has reported that he arranged for Mr Trump to meet Israeli Prime Minister Benjamin Netanyahu during the presidential campaign. Mr Kushner also reportedly wrote the speech used by Mr Trump when he addressed Aipac, the most prominent pro-Israel lobby in America.