Lord Sadiq Khan today made his latest push for Britain to rejoin the EU, warning that Brexit has been “catastrophic” for the capital.

The Mayor of London stressed that closer ties to Europe were more vital then ever as Vladimir Putin’s illegal war in Ukraine rages on and Donald Trump appears to have an “unsettling ambivalence” towards security on the continent.

It comes after a meeting with the London Business Forum to discuss how closer relations with the EU will help grow the city’s economy, create jobs and protect living standards.

In a letter to the Minister for European Relations, Hamish Falconer, Lord Khan called for a number of new agreements with Europe, including removing trade barriers for food and drink firms to support British exporters and help limit supermarket price rises.

He also said the Government should form an energy pact, involving emissions trading to help lower costs for households and businesses, a youth mobility scheme and an agreement to help touring musicians.

“Rejoining the EU must remain our destination,” the Mayor said.

“But there are also steps we can and must take now to rebuild our relationship with our European neighbours which would remove barriers to trade, grow our economy and improve living standards in the short-term.”

It follows Andy Burnham laying out his vision for undoing some of the harm of Brexit by seeking closer trade links with the EU.

The Prime Minister earlier this month said that deals on the table for a UK-EU summit on November 20 could give the British economy a £10 billion-a-year boost.

He stressed that the post-Brexit “status quo is not good enough” on UK-EU ties but insisted the British public will be the “boss” at every stage of renegotiating the relationship with Brussels.

Lord Khan said in his letter: “Brexit is, I believe, the greatest act of economic and geopolitical self-harm in our country’s history.

“Since we voted to leave the EU, the evidence for Brexit’s catastrophic consequences for London and the UK has continued to mount.

“As Putin’s illegal and unconscionable invasion of Ukraine enters its fifth winter, President Trump’s unsettling ambivalence towards European security can no longer be ignored.

“His fondness for unilateralism has shaken the foundations of the transatlantic alliance, making the US an increasingly unpredictable and unreliable ally.

“And now, as his reckless war in Iran pushes up prices for British households, the folly of cutting ties with our closest neighbours is clearer than ever.

“In the geopolitical and economic storm we now find ourselves in, Europe offers Britain not just a safe harbour but a huge opportunity for growth. If we are to seize that opportunity, we must set our red lines aside and rebuild our relations with the EU.”

City Hall-commissioned research released earlier this year estimated that London’s economy was £30 billion smaller than it would have been without Brexit.

This means Londoners are nearly £3,400 worse off on average, according to the analysis.

The latest City Hall work suggests the Britain’s economic gap with comparable EU economies could reach £250 billion by 2030.

Lord Sadiq said the conflict in Iran, Russia’s war in Ukraine and uncertainty over the United States’ role as an ally make closer European cooperation increasingly urgent.

Lord Khan added: “I have been clear that rejoining the EU is the only viable path to long-term prosperity and security for our country.

“Most of the recent studies advocate for us to rejoin the European Union to mitigate as much of the damage incurred so far as possible.

“This would also unlock a new age of growth and productivity and strengthen the UK geopolitically at a time of increased global uncertainty.”