Complex sentence: Announcing his attention to challenge McIntosh for leadership, he invited other members of the assembled caucus to stand for other posts, before the meeting came to an end at 4:45 in the afternoon, having agreed to support a full slate of candidates.
Split into simpler sentences: Announcing his attention to challenge McIntosh for leadership, he invited other members of the assembled caucus to stand for other posts. The meeting came to an end at 4:45pm having agreed to support a full slate of candidates.