a candidate for takeover, page-31

Westcott

If shareholders have been talking to each other about changing the board, then they would become associates and together would need to lodge a "becoming a substantial shareholder" as a collective.

Since I dont see any notice, I think you can discount that option.

Furthermore, no reason to call a trading halt if all the board received was an EGM notice from an existing substantial shareholder calling for a vote on their removal.