The EU has given Britain and eight other states until next Friday to show how they will comply with EU air pollution laws or face the European Court of Justice.
The ultimatum came as London reached its legal air pollution limit for 2018 in just the year’s first month, and could lead to heavy fines being imposed on the UK even after Brexit.
At a mini-summit in Brussels on Tuesday, the EU’s environment commissioner, Karmenu Vella, warned ministers from nine states that Brussels had lost patience and “drastic measures” would be needed to avoid court referrals next week.
“Deadlines for meeting these obligations have long since elapsed and some say we’ve already waited too long,” he told journalists after the meeting. “But we can delay no more.”
Pollutants such as nitrogen dioxide and particulates have been linked to an estimated 40,000 early deaths each year, according to the Royal College for Physicians.
“We urge member states to address this life-threatening problem with the urgency it deserves,” Vella said.
However, it could take as long as two years before any case is heard by the court, even though the UK has been in breach of the air quality directive since 2010.
The commission has moved slowly, waiting for a year after sending a reasoned opinion to the UK last February. But after finally moving, any fines levied could now be significant.
“If you take the seriousness and how long it’s been taking place for, it could be quite a big amount,” one EU source said.
Post-Brexit, the UK would still be liable to pay court fines handed down for offences committed when it was a member, in Brussels’ view.
“If the European commission takes the UK to court and the court takes a verdict on that, even if that verdict falls after the date of Brexit, logically speaking, the UK should still pay the fines for that,” an EU source told the Guardian.
Environment secretary Michael Gove skipped Tuesday’s meeting, but Thérèse Coffey, the under-minister replacing him, took a “constructive” tone, according to sources present at the table.
Seb Dance, Labour’s European environment spokesman said: “The situation is becoming embarrassing for a government supposedly committed to a so-called ‘green Brexit’.”
The threat of legal action “goes to show that the British government cannot be trusted to tackle air pollution on its own,” he added. “Who is going to protect British citizens’ right to clean air if we leave the EU?”
Germany, Spain, France, Italy, Hungary, Romania, Slovakia and the Czech Republic are the other states facing the ultimatum on illegal air pollution.