An A320's right wing inspection/scan light was inoperative during night and snow operations. The MEL prohibits release under these conditions; yet until the flight crew refused the aircraft; Maintenance was not inclined to repair the light.

Narrative

During preflight inspection; First Officer discovered right wing inspection/scan light inoperative. Captain called Maintenance Control via telephone and verbally informed them of issue. After arriving in the cockpit; a new Maintenance Release printed with no reference to wing light inoperative. Captain immediately sent Maintenance code via ACARS. Approximately 10 minutes later; Captain called Maintenance to ask about wing light repair. Maintenance Control informed Captain the issue would be deferred. I; the Captain; then informed him that I did not think it could be deferred given the conditions: night and snowing. He said he would review the MEL and get back with me. After approximately 5 minutes; we received an ACARS message from Dispatcher asking 'are you agreeable to go with the right wing scan light inoperative.' We replied; 'Negative.' During this; we received another Maintenance Release with the item deferred and an MEL printout stating; 'B. both lights must be operative for night operations where wing visual inspections are required.' How could a Maintenance Controller AND a Dispatcher each review the MEL item and defer this item on a snowy night? Additionally; we called and informed Maintenance that the item would need to be repaired. A Mechanic arrived in the cockpit and asked us if we were refusing aircraft. I said that we were not refusing the aircraft; but felt that an item had been deferred that could not be deferred given the conditions. He again asked us if we were refusing the plane. I stated if that was what was necessary to have the light repaired; then yes; we were refusing the aircraft. He promptly exited the plane. Soon 2 other Mechanics arrived and promptly and professionally replaced and tested the right wing scan/inspection light. I think this was an attempt to illegally defer an item. I don't see how; after verbally being told that the item could not be deferred given the conditions; Maintenance could review and sign off/defer an item that clearly states the above quoted restriction.