All clubs must have an appointed President and Treasurer, and they must have been elected by the members of the club/society at an AGM or EGM. Your Constitution will also lay out what other Committee members you have to have each year (known as the Principle Committee Officers). If at any time someone wishes to resign, there are procedures in place for this, and if you feel that a member of your committee is not pulling their weight then you may initiate a Vote of No Confidence to remove them from your committee. You should check the Club and Society Regulations for full details on all of this.
If a President or Treasurer chooses to resign before the end of their period of office they must submit their resignation in writing to the Student Activities Officer. All other committee positions may submit their resignation in writing to the President.
Following an early resignation of the President, Treasurer or other committee member, an EGM must be held. Another Officer may act as the President or Treasurer in the interim period. See the guides on How to organise an EGM or an AGM for full details on how to re-elect people to your committee.
A motion of no confidence in any Officer may be called in any committee, by either a petition signed by at least 15% of the membership of the club/society or 10 (whichever is greater), or by a two-thirds majority vote at a club/society committee meeting.
If a no confidence motion is called then an EGM must be held, and in order for the no confidence motion to be carried it must be supported by two-thirds of those present and voting. See the guides on How to organise an EGM for full details of how to organise an EGM.
If the no confidence motion is successful, then the President or Treasurer should immediately inform the Student Activities Officer. Your Club or Society will then need to hold another EGM to re-elect a new person to that position.