Possible Clues:

• Showing up with a surprisingly decent tan
• Audience two hours before midnight having a ball?
• All those present when the news is broadcast party
• Presence at function required by number
• Those there when the ball begins at 10.00
• Those on the ball at ten o'clock
• The Gate has seating for 370-odd
• Turning up at eight, dine, _ _, _ and, at twelve, go home?
• Approaching PM's house, swing gate
• Gate at the Roman cross ball