Swiss club FC Sion revealed Thursday that it has launched a legal action in Zurich against FIFA as its off-field battle with world football's governing body continues. The club's action is against FIFA's executive committee, which recently threatened to expel the Swiss Football Association (ASF) and all member clubs unless it punished Sion before Jan. 13 for breaching player recruitment rules. Sion has accused FIFA of “unacceptable blackmail” for attempting to force the ASF to take action that would “run contrary to their own rules and to Swiss law.” “The club cannot tolerate seeing other Swiss clubs taken hostage by FIFA,” read a statement published on Sion's website. On Tuesday, Sion urged the ASF to appeal against FIFA's threatened suspension, and said that “sacrificing” the club to satisfy FIFA would show a lack of courage and put in doubt the ASF and the Swiss Football League's ability to continue managing Swiss football. The row erupted after Sion, the subject of a FIFA-imposed transfer embargo over the signing of Egyptian goalkeeper Essam El Hadary, proceeded to sign six players in the summer. The club then fielded five of the six players during a Europa League play-off tie against Celtic earlier this year and were kicked out of the competition as a result, with UEFA's decision to expel them upheld by the Court of Arbitration for Sport. Ajax fan sentenced A Dutch court has sentenced an Ajax fan to six months in jail after he ran onto the pitch during a Dutch Cup match and tried to assault an opposition goalkeeper, a report said Thursday.