Former Birmingham co-owner David Gold has been banned from the directors' box and boardroom at St Andrew's for Saturday's clash with his current club West Ham.
Birmingham have taken the stance in response to Gold's comments in the Birmingham Mail on Friday about the club he was in charge of for 16 years along with David Sullivan. Gold described current City vice-chairman Peter Pannu as "disgusting" in the article.
Gold claimed that he was denied the chance to remain as chairman of Birmingham by Pannu after he and Sullivan sold the midlands club to Carson Yeung for Â£8.5million. Pannu has been adamant Gold was never guaranteed such a role and he later rejected the chance to be a vice-president.
City have sent a letter to West Ham saying Gold will not be welcome in the directors' box or boardroom on Saturday after his remarks.
It says the board "has taken the decision to withdraw Mr Gold's personal invitation to our fixture."
The letter adds: "He will therefore not be permitted to enter the directors' seating or boardroom area.
"The board feel that they are left with no other option but to withdraw Mr Gold's invitation and that this is the appropriate action to take.
"In addition, the board are also mindful of potential security issues for Mr Gold and a possible adverse reaction that may arise from the Birmingham supporters as a result of the comments made.
"Furthermore, as [club owner and president] Carson Yeung will also be flying in for the game, the board felt that a harmonious boardroom environment should not be affected as we all want a good atmosphere on the day and a good game of football."
It remains to be seen whether Gold will try to attend in a non-official capacity, but he admitted on Thursday to the Birmingham Mail that he had "some trepidation" about going to the fixture.