Possible Clues:

• Former PM's aim to replace Liberal who might make his presence felt?
• Pay attention to the ease one goes to a conference
• Someone who is here
• One present at a particular hour on the river
• One present (at event)
• One shows up old PM with ambition ousting Liberal
• Concertgoer
• One who is present
• One who's come with a temperature ... nurse, notes!
• One at conference has to listen to same point repeatedly