Possible Clues:

• Greek island providing my entertainment mostly
• Greek island where Prince Philip was born
• Vacation spot in the Ionian Sea
• Union organisers supporting firm's idea for holiday
• Dress up mostly on upper-class holiday island
• My enjoyment is limited in foreign island
• Running up short dress acceptable for Greek island
• One of the Ionian islands
• Birthplace of Prince Philip
• Tourist destination in the Ionian Sea