Her image has been symbolic of the national mood once before. Recreating a 19th-century masterpiece of Lady Liberty leading the French to revolution, a statuesque portrait of Caroline de Bendern emerged as a defining image of the protests that swept Europe in the summer of 1968.

Now almost five decades on, the British former model and disinherited aristocrat is taking to the streets again – to demonstrate her opposition to Brexit and fly the flag for the European Union at this week’s Unite for Europe march.

Demonstration in the Quartier Latin in Paris, 1968. Caroline de Bendern holds a Vietnamese flag on the Boulevard Saint-Michel. Photograph: Jean-Pierre Rey/Gamma-Rapho via Getty Images

Thousands of pro-EU protesters are expected at marches in Edinburgh and London on Saturday, where speakers will include the Liberal Democrat leader, Tim Farron. De Bendern says the atmosphere will be different from her first foray into political action. In 1968, “there wasn’t all this hate,” she said.

The March-June protests brought together students, artists, leftists and workers demanding better working conditions, sexual liberation, and political and social reform. Political change and cooperation was similarly needed today, she said. Now 76 and living in France, De Bendern told the Guardian she was concerned at Britain breaking away from the EU at a time of Russian activism.

“We need to form a bloc against countries like Russia who want to destroy Europe and ... absorb it,” she said, recalling allegations of Russian interference in the EU referendum and the US presidential elections. “Why would they interfere in the referendum if they haven’t got some idea behind it?” With the future of the union under strain, she said, “England is going to become isolated”.

“The whole [leave campaign] was lies and xenophobia,” said De Bendern, who dated rock musician Lou Reed in New York and counted artist Andy Warhol and model Nico as friends.

The activist also voiced concerns about her status as a British national in France. She said she loved Britain, where she visited family two or three times a year, but had lived in France since 1968 and was applying for dual nationality in case her ability to live in France was jeopardised by Britain’s exit from the EU. She said she is “scared shitless” of an election win by Marine Le Pen, who has threatened to introduce restrictions on dual nationality.

Liberty Leading the People, by Eugène Delacroix

“If there has to be a Brexit … like the jazz tune Soft Journey by Enrico Pieranunzi and played so beautifully by Chet Baker, if you have to do it, please make this journey soft. Please don’t cut us off completely from the EU,” she said.

On Saturday in London, De Bendern will be carrying an EU flag in a nod to the 1968 image. The photograph drew immediate comparisons with Liberty Leading the People, an 1830 painting by Eugène Delacroix commemorating the French revolution against King Charles X.

The image of De Bendern as a young woman holding a Vietcong flag – at the height of opposition to the US’s war against Vietnam – over a sea of young protesters, was reproduced nationally and internationally. But she paid dearly for the photo. Her grandfather cut her out of his will, which reportedly cost her £7.5m, and her modelling career also suffered. She left Europe to make a film in Africa shortly afterwards.

“If you hold a flag, you obviously think about that [Delacroix] painting,” she said, as she prepared to head to London for this weekend’s protest. Would she have done anything differently to recreate the masterpiece? “I should have bared my breast. She had such awesome breasts.”