FRICTION at the U.K. border is rising again following Brexit as shipping companies rejected more cargoes due to cross the English Channel from France.

The rate that freight companies declined to take shipments that were scheduled to move rose last week and is now 69 percent higher than the average in the third quarter, according to the logistics platform Transporeon.

“Uncertainty in the transport market” is increasing, especially on the France-to-U.K. route, said Transporeon chief executive Stephan Sieber.

The figures add to evidence of constraints on Britain’s ability to trade goods in the next few months. Those tensions are likely to increase starting in April when the European Union phases in full customs checks, threatening to increase delays at ports and hold up imports.

The figures “can’t be fully chalked down to teething problems,” said James Smith, an economist at ING Bank. “The economy is still adjusting to big changes” following Britain’s decision to leave the EU.

Britain rejected the idea that friction is building at the border and said that it’s focused on helping businesses comply with new customs rules.

“Our management information shows that overall freight flows between the U.K. and the EU are back to their normal levels,” a government spokesperson said. “Our focus now is on making sure that any business that is still facing challenges gets the support they need to trade effectively with the EU.” (SD-Agencies)