The latest warning of the economic implications of leaving the European Union came as more opinion polls suggested the Leave campaign would succeed next week.
The Bank’s intervention also saw its governor, Mark Carney, insist he has every right to comment on the economic impact of withdrawal after being accused of breaking impartiality rules by a leading Leave campaigner.
The Bank insisted it is “increasingly probable” a Leave vote in next week’s referendum would sharply damage the value of sterling across international money markets.
Financial experts warned uncertainty surrounding the outcome of the poll is already forcing consumers to put off “major economic decisions” and provoking a slowdown in house and car sales.
The Bank insisted the referendum remains the “largest immediate risk” facing financial markets, as its monetary policy committee decided to hold interest rates at the 0.5 per cent level they have been at since March 2009.
In spite of the severity of the economic warnings being issued, the Leave campaign is continuing to gain ground.
According to a Ipos Mori poll published yesterday, the Leave campaign has a six-point lead over Remain. The telephone poll of 1,257 adults showed that when undecided voters are excluded, 53 per cent want the UK to quit the EU and 47 per cent want to stay.
According to the poll, immigration has overtaken the economy as the most important issue influencing how people intend to vote – a state of affairs that will be seen as a boost to Boris Johnson and the Leave campaign.
The survey’s findings were backed up by a Survation poll, which put support for Leave on 45 per cent, compared with 42 per cent for Remain.
The Survation poll represented an increase of seven percentage points for Leave since last month. Leave increased its lead from 38 per cent. Over the same period Remain fell by two points.
The Bank of England re-entered the referendum debate following a dispute between Mr Carney and prominent Conservative MP and Leave campaigner, Bernard Jenkin.
Bank sources revealed Mr Carney considers a letter from Mr Jenkin stating that the governor had made his views on the referendum public despite strict impartiality rules to be a “political threat”.
Mr Jenkin – who is chairman of the House of Commons public administration committee – hit back by branding the governor “very aggressive”.
In a strident response, Mr Carney said that Mr Jenkin’s letter contained “numerous and substantial misconceptions”.
Mr Carney also accused Mr Jenkin of having a “fundamental misunderstanding” about the independence of the Bank.
The governor said he had not “made my views known” on the referendum.
He wrote: “All of the public comments that I, and other Bank officials, have made regarding issues related to the referendum have been limited to factors that affect the Bank’s statutory responsibilities and have been entirely consistent with our remits.”
Mr Jenkin said Mr Carney’s intervention in the referendum debate has gone “way beyond what a Bank governor would normally do”.
He told BBC Radio 4’s Today show: “He’s reacted very, very aggressive towards me.
“There is no doubt that the appearance he made on the Andrew Marr programme went way beyond what a Bank governor would normally do in terms of making statements about rate setting and economic forecasts.
“I obviously misconstrued that because in my letter to him I said he had made his views clear that he wants the United Kingdom to stay in the European Union.”
But Lord Darling, Labour ex-chancellor, accused Mr Jenkin of engaging in a “blatant attempt to muzzle a respected independent voice”.
Meanwhile, Labour leader Jeremy Corbyn suggested that supporters of his party may be backing the Brexit option because they do not understand what Leave would mean.
He said: “I think a lot of people haven’t understood the relationship with the European Union, haven’t appreciated the amount of investment that’s come in to many parts of this country.
“I think that many people don’t realise that the implications of voting to leave on the 23rd could be quite serious – could be quite serious in export industries that rely on selling goods across Europe.”
Despite growing calls in Labour’s top team for reform of free movement of workers’ rules, Mr Corbyn insisted: “The European Union actually depends on the movement of people across the continent.”
European Commission president Jean-Claude Juncker has warned UK voters “would be best advised” to oppose Brexit.
Speaking in St Petersburg, Russia, he said withdrawal would spark “a period of major uncertainty” for both Britain and the EU.