Yoane Wissa has held crunch talks with Brentford director of football Phil Giles, during which he threatened not to play for them again if he is not allowed to move to Newcastle, a source has told BBC Sport.
Bees forward Wissa is the subject of major interest from the Magpies, who have already had one offer turned down for the 28-year-old.
Wissa flew back from the club's pre-season training camp in Portugal earlier this week for talks with Giles, as he made clear his intention to move to St James' Park.
Brentford are yet to sanction his transfer to the north-east, which, sources claim, has annoyed Wissa.