Possible Clues:

• 'Let me sleep on it'
• Regulars in navy, inspired by honour — it's a possibility
• See 8 Down
• ... reportedly an earlier insect, perhaps?
• Possibly become empty after a month
• "Perhaps"
• Picked up morning Times, upset over Spain, perhaps
• Prime Minister, extremely believable? Perhaps
• It's not a lock
• Third of three choices