West Ham co-owner David Sullivan has told new manager Big Sam his job is safe, after just one day in charge.
Allardyce was unveiled as the man Sullivan and partner David Gold had chosen to spearhead the club's attempts to return to the Premier League yesterday.
He agreed a two-year deal with the Upton Park club but, hours after his appointment, businessman Tony Fernandes wrote on his Twitter account that he was making a bid for the club.
Sullivan told The Sun: "The whole thing is nonsense. I can assure Sam he has an unbreakable two-year contract and he is the perfect man for the job.
"I can only think the motivation for this 'takeover' bid is PR. If there was a genuine Russian billionaire out there willing to pump hundreds of billions of pounds into West Ham then we'd step aside for the good of the club.
"But when someone offers to buy your club for buttons and does it via Twitter it is most unhelpful at a time when we are trying to rebuild West Ham."