An 81-year-old woman is suing Israeli airline El Al for discrimination after she was allegedly forced to move seats because an ultra-Orthodox man refused to sit next to her.

Renee Rabinowitz, a retired lawyer who lives in Jerusalem, was settled in her aisle seat in the business class section of Flight 028 from Newark to Tel Aviv last December.

However, when a man assigned the window seat on her row showed up and did not want to sit next to a woman, a flight attendant offered Rabinowitz, who walks with a cane, a "better" seat to accommodate the man's religious beliefs.

Physical contact between men and women is not allowed outside of marriage in the ultra-Orthodox tradition.

'Despite all my accomplishments -- and my age is also an accomplishment -- I felt minimized,' Rabinowitz, who has a Ph.D in educational psychology, told The New York Times.

"For me this is not personal," she added. 'It is intellectual, ideological and legal.

"I think to myself, here I am, an older woman, educated, I've been around the world, and some guy can decide that I shouldn't sit next to him. Why?"

Rabinowitz who fled with her family from Nazi-occupied Belgium in 1941, is now filing a lawsuit against the airline.

Liberal advocacy group The Israel Religious Action Center (IRAC) has taken up her case.

"We needed a case of a flight attendant being actively involved," IRAC's director, Anat Hoffman told the Times "to show that El Al has internalized the commandment, 'I cannot sit next to a woman."

The grandmother said during the December 2 flight the flight attendant had a brief conversation with her seatmate-to-be, which she could not understand, before she was offered the other seat.

When she asked the flight attendant if he was suggesting her to switch seats was because the man wanted her to move, Rabinowitz said 'without any hesitation" he said "yes," according to the Times.

Later when she returned to her original seat to collect her hand luggage she said she asked the man why it mattered and he replied, "it's the Torah," she said.

She noted there was no other seat available for him next to a man.

An El Al spokeswoman responded to the Times in a statement saying that any discrimination between passengers is prohibited.

"El Al flight attendants are on the front line of providing service for the company's varied array of passengers," the statement said.

"In the cabin, the attendants receive different and varied requests and they try to assist as much as possible, the goal being to have the plane take off on time and for all the passengers to arrive at their destination as scheduled."

A lawyer for the IRAC wrote a letter to the airline accusing El Al of illegal discrimination and demanded 50,000 shekels (US$13,000) in compensation for Rabinowitz, according to the Times.

El Al offered US$200 of her next flight instead and insisted that the flight attendant it made it clear she was not obligated to move and noted she had changed seats without argument.

The ultra-Orthodox tradition regarding physical contact between men and women has led to other incidents on planes including in 2014.

At the time several flights from John F Kennedy International Airport Airport to Tel Aviv were delayed when ultra-Orthodox male passengers refused to sit next to women prior to takeoff.

The tactic not only delayed the flight, but also went onto cause chaos on board.

And most recently, an Orthodox-Jewish Israeli was arrested after going on a rampage and smashing up passenger plane equipment when an 'immodest' film, Truth, was shown during a flight from Poland.