Boris Johnson waded in to the row between steel tycoon Lakshmi Mittal and the French government today as he urged Indian businessmen to set up in the United Kingdom.
He called French industry minister Arnaud Montebourg, who accused Mr Mittal of leaving the country after he announced the closure of two blast furnaces in the north-eastern region of Florange, an "eccentric", telling an audience of businessmen in Delhi they should avoid "persecution" in Paris and base their European operations in London.
The row erupted after the socialist minister Mr Montebourg said ArcelorMittal - the world's biggest steelmaker owned by Mr Mittal - had shown a lack of respect to France.
"We don't want Mittal in France anymore because they haven't respected France," Mr Montebourg was quoted as saying in the business newspaper Les Echos. The trouble, he said, "isn't the furnaces in Florange, it's Mittal".
Mr Mittal has considerable business interests in France.
The comments were seized upon by Mr Johnson, who is on the third day of his six-day tour of India.
He told a meeting of businessmen in Delhi: "On a day when the sans-culottes appear to have captured the government in Paris and a French minister has been so eccentric as to call for a massive Indian investor to depart from France, I have no hesitation or embarrassment in saying to everyone here 'venez a Londres, mes amis'.
"Come to London, come to the business capital of the world, the place where 73 Indian firms are listed on the London Stock Exchange, where Indian companies already raise 53% of their international equity, a city that has the largest banking and financial sector anywhere in the world, but which is at the cutting edge of all the great growth businesses of the 21st Century."
The sans culottes were a radical faction in the French Revolution.
Mr Johnson added: "I have a simple message for everyone here, our Indian friends. Following the demarche of Monsieur Montebourg, who is obviously cheesed off by what is happening in the eurozone, don't wait to be persecuted by the sans-culottes in Paris. Don't wait to be put in the tumbrels by the regime of Monsieur Hollande. Venez a Londres."
According to the Financial Times, sources close to Mr Mittal, one of the world's richest men, said he was "extremely shocked" by the attack against the company of which he is the main shareholder.