Allardyce, who has led the national side for barely two months and just one match, has been sacked after being filmed by the Daily Telegraph as part of its investigation into alleged corruption in football.
The Daily Mail reported Allardyce would announce his resignation by the end of the evening.
Videos released by the Telegraph show 61-year-old Allardyce appearing to make a variety of indiscreet and controversial comments to undercover reporters posing as businessmen, and the broadsheet newspaper has agreed to share more detailed findings with the FA.
While Allardyce is seen talking in unguarded and potentially damaging fashion about his predecessor Roy Hodgson, former assistant manager Gary Neville and his selection policy involving individuals, the most serious issues appear to be his apparent willingness to pursue a £400,000 deal to address investors in the Far East and his views on the outlawed practice of third-party ownership.
"We will release to the FA the relevant transcripts of our investigation into football corruption," a Telegraph statement read. "These run to many hundreds of pages so will take some time to collate."
The contents of the transcripts involving Allardyce will be a matter of pressing interest to the likes of FA chairman Greg Clarke and chief executive Martin Glenn, who were reported to be holding emergency meetings at Wembley throughout Tuesday.
Board member David Gill, part of the three-man panel that selected Allardyce as Roy Hodgson's successor alongside Glenn and technical director Dan Ashworth, was pictured at the national stadium but there was no confirmed sighting of Allardyce, who is based at St George's Park in Staffordshire.
The former Bolton, West Ham and Sunderland boss left his home in Bolton shortly before 7am without comment but 12 hours later had yet to emerge in public.
The FA has yet to make any official statement, but Press Association Sport understands a sacking outcome would not come as a big surprise to some in the England dressing room.
The Telegraph's video seemingly shows Allardyce discussing a lucrative deal to act as a "keynote speaker" for overseas investment groups, with a caveat that he would "have to run it past the powers that be".
The England manager was filmed offering an account of how to circumvent third-party ownership regulations, saying it was "not a problem" to get around FA rules which stop third parties "owning" football players' economic rights.
The controversial practice was banned by the FA in 2008 over concerns it compromised the integrity of the game, as the third party could profit whenever a player was sold.
He added an unnamed group had been "doing it for years" and "you can still get around it", suggesting they employ the player's agents to compensate for the fact they are no longer allowed to profit from each transfer directly.
"You get a percentage of the player's agent's fee that the agent pays to you, the company, because he's done that new deal at the club again or they sell him on, and you're not getting a part of the transfer fee any more, because you can't do that," Allardyce says.
"But, you get - because of the size of the contracts now, the contract will be worth 30, 40million, at 10 per cent and you've done a deal with the agent where you're getting five per cent of the agent's fee, which is massive for doing about two hours' work."
The footage makes for uncomfortable viewing and former England striker Gary Lineker posted on Twitter: "Biggest issue for Sam Allardyce is advising on getting around 3rd party rules. As well, of course, as very poor judgement."
The principles and standards of behaviour set out by the FA in its England DNA philosophy, a plan built with the aim of creating winning England teams, has four key components: pride, excellence, collaboration and integrity.
Under the integrity header, it says: "We strive for the highest standards on and off the field. Nothing less is acceptable."
Allardyce is reported to have been filmed discussing the gambling habits of the country's current or former senior internationals, the chances of players lining up for England, Hodgson's assistant Gary Neville, Prince Harry and the Duke of Cambridge.
The meeting with the undercover reporters also saw Allardyce appear to be filmed questioning predecessor Hodgson's decisions at Euro 2016, at times calling him "Woy" - a word used in a headline in 2012 that the FA called "unacceptable" and relating to the former England manager's rhotacism.
On his employers, the FA, the video seems to show the England boss saying "they're all about making money", but are not the richest football association in the world as "they stupidly spent £870million on Wembley, so they are still paying that debt off'".
New information released by the Telegraph on Tuesday claims Allardyce also complained about the United Kingdom's tax system, taking aim at HM Revenue and Customs.
The England boss was reported to have said: "The most corrupt business in our country would be what? You'll be shocked when I tell you this - HMRC."
Allardyce, who led Sunderland to Premier League survival last season, was appointed England manager on July 22 after what the FA called a "comprehensive and structured process".
His England reign got off to a winning start earlier this month with a 1-0 World Cup qualifying win in Slovakia. Further qualifiers follow at home to Malta on October 8 and in Slovenia three days later.