Barack Obama's intervention in the EU referendum debate is a "piece of outrageous and exorbitant hypocrisy", Boris Johnson has claimed
The US president's warnings that Britain will lose influence on the world stage if it quits the 28-member bloc are also "wholly fallacious", according to the London Mayor.
New York-born Mr Johnson attacked the US for interfering in the debate, when it defends its own sovereignty with "hysterical vigilance".
Downing Street has refused to comment on reports that the US president, who has previously made it clear that America wants its closest ally to remain part of the EU, is heading to the UK next month to make the case to voters.
In his regular Daily Telegraph column, Mr Johnson wrote: "Sometime in the next couple of months we are told that president Obama himself is going to arrive in this country, like some deus ex machina, to pronounce on the matter.
"Air Force One will touch down; a lectern with the presidential seal will be erected. The British people will be told to be good to themselves, to do the right thing. We will be informed by our most important ally that it is in our interests to stay in the EU, no matter how flawed we may feel that organisation to be.
"Never mind the loss of sovereignty; never mind the expense and the bureaucracy and the uncontrolled immigration. The American view is very clear. Whether in code or en clair, the president will tell us all that UK membership of the EU is right for Britain, right for Europe, and right for America; and why?
What has the EU ever done for us?
What has the EU ever done for us?
1/7 1. It gives you freedom to live, work and retire anywhere in Europe
As a member of the EU, UK citizens benefit from freedom of movement across the continent. Considered one of the so-called four pillars of the European Union, this freedom allows all EU citizens to live, work and travel in other member states.
2/7 2. It sustains millions of jobs
A report by the Centre for Economics and Business Research, released in October 2015, suggested 3.1 million British jobs were linked to the UK’s exports to the EU.
3/7 3. Your holiday is much easier - and safer
Freedom to travel is one of the most exercised benefits of EU membership, with Britons having made 31 million visits to the EU in 2014 alone. But a lot of the benefits of being an EU citizen are either taken for granted or go unnoticed.
4/7 4. It means you're less likely to get ripped off
Consumer protection is a key benefit of the EU’s single market, and ensures members of the British public receive equal consumer rights when shopping anywhere in Europe.
5/7 5. It offers greater protection from terrorists, paedophiles, people traffickers and cyber-crime
Another example of a lesser-known advantage of EU membership is the benefit of cross-country coordination and cooperation in the fight against crime.
6/7 6. Our businesses depend on it
According to 71% of all members of the Confederation of British Influence (CBI), and 67 per cent of small and medium-sized enterprises (SMEs), the EU has had an overall positive impact on their business.
7/7 7. We have greater influence
Robin Niblett, Director of think-tank Chatham House, stated in a report published last year: “For a mid-sized country like the UK, which will never again be economically dominant either globally or regionally, and whose diplomatic and military resources are declining in relative terms, being a major player in a strong regional institution can offer a critical lever for international influence.
"Because that - or so we will be told - is the only way we can have 'influence' in the councils of the nations. It is an important argument, and deserves to be taken seriously. I also think it is wholly fallacious - and coming from Uncle Sam it is a piece of outrageous and exorbitant hypocrisy.
"There is no country in the world that defends its own sovereignty with such hysterical vigilance as the United States of America. This is a nation born from its glorious refusal to accept overseas control."
Mr Johnson, meanwhile, has come in for criticism from George Osborne for suggesting Britain could achieve a Canadian-style trade deal. The Chancellor insisted the agreement took seven years to negotiate and tariffs on exports remain in place for cars and beef.
"I hear people saying 'I want Britain to be like Switzerland, I want Britain to be like Norway, I want Britain to be like Canada'. You know what? I want Britain to be like Great Britain'," Mr Osborne told BBC One's Andrew Marr Show.
Mr Osborne also appeared to take a more personal swipe at the mayor, who came in for criticism over his performance during a recent appearance on the programme.
"If people want a politician who is just going to sit here and blather away and not actually do anything, then get someone else," he said.