An angry war of words has exploded between Bank of England Governor Mark Carney and a leading Leave campaigner regarding referendum impartiality rules.
Mr Carney considers a letter from Tory MP Bernard Jenkin to be a "political threat", while the Vote Leave director hit back by branding the governor "very aggressive".
The spat erupted when Mr Jenkin, who is chairman of the Commons Public Administration Committee, wrote to the governor stating that Mr Carney had made his views on the referendum public, and reminding the Bank about impartiality regulations.
In a strident response, Mr Carney said the letter - which Bank of England sources consider a "threat" - contained "numerous and substantial misconceptions".
Mr Carney also accused Mr Jenkin of having a "fundamental misunderstanding" about the independence of the Bank.
The governor wrote: "I have not 'already made [my] views known about the question in the forthcoming referendum'. Nor do I intend to share my private opinion other than via the anonymity of ballot box when I join millions of others to cast my vote.
"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.
"The Bank has a duty to report our evidence-based judgments to Parliament and the public. Indeed that responsibility to provide a high level of transparency is enshrined in our remits."
The EU referendum campaign is currently in a period of purdah, which bans civil servants from any activity that could be perceived to be biased to one side of the campaign.
Mr Jenkin said Mr Carney's intervention in the referendum debate has gone "way beyond what a Bank governor would normally do in terms of making statements about rate setting and economic forecasts".
He told BBC Radio 4's Today show: "He's reacted very, very aggressive towards me.
"He's trying to make a distinction that the Bank of England does not run on public funds, even though it's a publicly-owned corporation.
"The advice I have from the Speaker's Counsel is that there appears to be no exemption for the Bank of England."
Mr Carney has insisted his economic warnings were independent of politics.
Appearing to back away from his accusations, Mr Jenkin added: "It's for him to judge how political he wants his institution to be perceived as.
"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."
Labour ex-chancellor Alistair Darling condemned the stance of Mr Jenkin.
"This is a blatant attempt to muzzle a respected independent voice. The Bank of England is independent, the governor is independent and he has a duty to say what he thinks," he said.
"It is very clear the Leave campaign doesn't want people to hear what the Bank has to say on the most critical issue facing our generation because they don't like its conclusions."