Scott Wightman, Britain's outgoing senior diplomat in Singapore, has said that he is a world besieger by division, obsessed with ideology and careless of truth.
In a valedictory note, he compares with the fall of Singapore in 1942 and said major investors expect future investment in Europe to be directed towards Germany and France.
The remarks, first reported by Politico, came as a high commissioner in his native Scotland.
Ironically, many Brexiter MPs have claimed the UK can become a free-market haven like Singapore's once-in-a-lifetime policy.
Wightman said that it was a result of the nation that Singaporeans "admired for stability, common sense, tolerance and realism grounded in fact, they see beset by division, obsessed with ideology, careless of the truth … I fear many around the world share their view. "
Wightman has been one of the UK's most senior diplomats in Asia, first Asia-Pacific director in the Foreign Office and then the UK ambassador in Seoul, South Korea. He has been a high commissioner in Singapore since 2015.
At his farewell speech marking the Queen's birthday, the United Kingdom and the United States of America.
In his memo Wightman said: "Like posts across the network and departments in the UK, we're performing minor miracles for UK's interests with the utter political shambles of Brexit," he said. Singaporean ministers are "mystified as to our political leaders allowed to get to this pass".
He described the Singapore-UK Partnership for the Future, an initiative to improve the position of the foreign secretary, Jeremy Hunt, in January, as being used in the "classic manner of the illusionist".
Wightman said post-referendum political risk is now overseas investors' "main consideration". He likened Brexit's impact to the fall of Singapore in 1942, the largest British surrender in history and the battle that showed the "complacency and arrogance of colonial leadership".
"It transformed their view of British imperialism," he added. "Things were never the same again. The last three years have been done for the Singaporeans' view of contemporary Britain.
He said that the UK is enjoying a deep-seated relationship with the UK, and that it could be expected to work constructively with the UK irrespective of Brexit. However, he said: "Whatever we may say in public about global Britain, we must not be kidnapped in the world of the world."