An EU chart appears to misrepresent the U.K.'s scale when it comes to trade | Tolga Akmen/AFP via Getty Images Sliding flaws: EU publishes misleading Brexit chart Chart appears to exaggerate the size of UK trade with the EU compared with Japan’s.

Brussels' latest salvo in a war of slides with the U.K. could backfire.

The European Commission on Wednesday published new slides to hit back at the U.K. government's insistence that it should be offered the same deal as Canada, and included a chart that appears to be misleading.

In the presentation, titled “U.K. is different from other trade partners,” the Commission made the point that Britain's trade with the EU is larger than that of Canada, Japan, Switzerland or Korea.

The new chart features bubbles that it said represents each country's "trade volume with the EU." But the U.K. bubble appears much bigger than the trade volumes would allow for.

POLITICO asked the Commission for the underlying figures, which underscored the problem.

#Brexit battles: EU hits back at U.K., saying Britain cannot be treated like Canada because it's much closer (33 km vs. 5000 km) and exports to EU are "considerably" bigger (€197 billion vs. €125 billion for Canada, Japan and South Korea together). https://t.co/TIZXoJEcT7 pic.twitter.com/oTugf9rBb1 — Hans von der Burchard (@vonderburchard) February 19, 2020

Take Japan: Its trade volume with the EU stood at some €117.1 billion in 2018, compared with the U.K.'s €516.6 billion. That means the bubble representing the U.K. should be about 4.4 times larger than the bubble representing Japan. On the EU's chart, the U.K. bubble is more than 16 times larger than Japan's.

David Spiegelhalter, a professor of the public understanding of risk at Cambridge University, said the Commission's approach was "indefensible" and goes against "standard graphical practice."

"It's also the biggest mistake to make. It's incorrect to use diameter to represent volume," he said, adding that it was "the sort of thing a junior person would do."

Kevin McConway, emeritus professor of applied statistics at the Open University, said the chart is "horribly misleading."

"The U.K. does have more trade with the EU27 than each of the other countries shown, but nowhere near as much more as you’d think from looking at this," he said, "If you’re going to use data to make a point, do use it properly."

The Commission insists it did not purposefully manipulate the chart to exaggerate the difference between the U.K. and the other countries. Asked about the apparent mismatch, the Commission spokesperson said there was "no mistake."

“The purpose of today's slide is for information and presentational purposes only," the spokesperson said. "The chart was generated with an Excel chart tool, based on data from Eurostat. The width of each bubble is proportionate to the total trade of each country."

Spiegelhalter said the Commission should acknowledge the mistake and correct the chart. "You should own up to it. The worst thing you can do is try to stick to it," he said.

James Randerson contributed reporting.