French leaders are openly plotting to peel off large chunks of the City’s financial industry as soon as Britain leaves the EU. This might prove much tougher than they imagine.

The plans conflict with far more important economic and strategic objectives of the EU, and some of the stated intentions violate existing EU law.

France is rolling out the red carpet for putative refugees from Canary Wharf, hoping to capture the lion’s share of the estimated €600bn to €1 trillion market for clearing in euro-denominated transactions. Some German officials are also eyeing the City, but more discreetly.

"There is a power play going on. It is very clear France and Germany will do everything they can to damage the City and get the business for themselves," said Professor Athanasios Orphanides, a former member of the European Central Bank's governing council.

"But I don't think anybody can kill the City that easily. The EU itself is so messed up right now and the eurozone is so fragile that any shock could tip them over the edge, and when it happens it is going to be non-linear," he said.