Britain’s exit from the European Union has so far made trade more expensive because of delays and red tape, and more border disruptions are likely as passenger numbers recover after the COVID-19 pandemic, a parliamentary committee said on Wednesday.

Supporters of Brexit said exiting would allow the United Kingdom the independence to escape what they cast as a stagnating German-dominated project that was falling far behind big powers such as the United States and China.

But opponents of Brexit cautioned that leaving the EU was akin to an act of self-harm that would leave the United Kingdom diminished, poorer and more insular.

While trade was suppressed by the COVID-19 pandemic and other global supply constraints, parliament’s Public Accounts Committee found that the “EU exit has had an impact, and that new border arrangements have added costs to business”.

“One of the great promises of Brexit was freeing British businesses to give them the headroom to maximise their productivity and contribution to the economy,” said Meg Hillier, chair of the committee.

“Yet the only detectable impact so far is increased costs, paperwork and border delays.”

The leaders of Brexit said that in the short term there could be additional costs as the United Kingdom adapted, but in the long term there would be considerable political and economic benefits from leaving the bloc.

Asked about the report, Prime Minister Boris Johnson’s spokesman said traders and hauliers had adapted well to the changes and insisted there had been minimal disruption at the border.

“Given the continued impact of the global pandemic on global supply chains it is still too early to draw any firm conclusions on the long term impacts of our new trading relationship with the EU,” he added.

The Public Accounts Committee cautioned that the government had considerable work to do to make cross-border trade easier for businesses and that there were concerns about computer systems being developed by customs.

In November, Britain became the last Group of Seven developed nation to see its goods exports surpass their 2018 average level since the onset of the COVID-19, underlining its poor trade performance in international terms.