PARIS (AFP) - US civil rights leader Jesse Jackson and Jean-Marie Le Pen were feuding on Twitter on Wednesday after the French far-right firebrand posted a picture of them together at a Paris restaurant.

Le Pen on Tuesday tweeted a photo of the two men at a Moroccan restaurant, along with a note apparently handwritten by Jackson reading: "May 8-'16. Jean-Marie, (wife) Jany Le Pen, Keep Hope Alive, Continue".

But Jackson said he had unwittingly dined with the French politician on Sunday, tweeting: "Did not know you were coming to dinner. Never met you before. Do not share your beliefs."

"Keep Hope Alive" was a catchphrase the Baptist minister used during his unsuccessful 1988 bid for the US presidency.

Le Pen, co-founder of the xenophobic National Front (FN) party now run by his estranged daughter Marine, followed up with another picture in which a smiling Jackson is sitting at a table between Le Pen and his wife.

It is accompanied by the tweet: "Attention media who speak of 'imagined dinner'", with the hashtag #desinformation" - the French word for disinformation.

An aide to Le Pen told AFP the dinner was organised by mutual friends.

Jackson "knew he was going to dinner with Jean-Marie Le Pen and who he was," the aide said.

"There was no trap, and there was even an agreement with their mutual Moroccan friends that the dinner was not private. The photos were taken by a professional photographer."

Jackson, 74, attended events on Tuesday alongside French President Francois Hollande and Prime Minister Manuel Valls marking France's slavery remembrance day.

He laid a wreath at the tomb of Victor Schoelcher, who led France's abolitionist movement.

Le Pen, 87, was kicked out of the anti-immigration FN for refusing to tone down racist and anti-Semitic comments.

Marine Le Pen has since presided over an unprecedented rise in the party's fortunes, with many pollsters predicting the FN will make it to the second round of the presidential election next year.

Her father managed this feat in 2002, coming in second ahead of Socialist Lionel Jospin before losing to the conservative Jacques Chirac.

The Le Pen aide said Jackson "was often accused of anti-Semitism, accusations that he shares with Mr Le Pen. Maybe his entourage is worried" over the publicity from the dinner.

Jackson was criticised in the early 1980s for his ties to black nationalist leader Louis Farrakhan, known for his anti-Jewish rhetoric.

He also apologised in a speech before national Jewish leaders for using a pejorative term for Jews in remarks to a Washington Post reporter in 1984.

Le Pen was fined €30,000 last month for repeating his view that the Nazi gas chambers were a "detail" of history.