Possible Clues:

• Hard to swallow food requested -- not a piece of cake
• Brothers over six feet? Too much to ask
• 'Stand up straight' in hole?
• Challenging request
• Asphalt covering fifties ring road the ultimate sticky assignment
• Story right about Creator's formidable task
• Request to tax aristocrat opening account with rupees
• Tough assignment
• *Tough request from a customer (4 to 7)
• Fresh alert covering liege is a lot to ask