David Haye's controversial heavyweight showdown with Dereck Chisora has come under more pressure with the World Boxing Council backing the British Boxing Board of Control's hardline stance on the bout.
WBC president Jose Sulaiman has threatened to expel any person or organisation involved in the July 14 contest, which has been sanctioned by the little-known Luxembourg Boxing Federation.
Neither Haye nor Chisora is currently licensed by the BBBofC, and the BBBofC have already indicated that they will immediately rescind the existing licences of anybody involved in the promotion.
In a letter from the WBC to the BBBofC, Sulaiman said: "We will expel Luxembourg from our organisation if the commission went ahead as well as any person or institution that has relations with them.
"We will not condone such disgraceful behaviour (from Chisora) after seeing this boxer has no idea of what good behaviour is, by accepting to participate in the intent to threat (sic) and embarrass the organisation of boxing with such an act.
"I am sure the European Boxing Union is on the verge of a strong position against Luxembourg."
While the WBC's threat alone is unlikely to put off the promoters of the contest, who already boast 20,000 ticket sales for the Upton Park showdown, it could have wider repercussions for the boxers.
Haye in particular has been chasing a rematch with reigning WBC champion Vitali Klitschko but would effectively be ruled out of a contest if the organisation carried out their expulsion threat.