By Jack Mendel The chief executives of nine major pub and bar chains have written to rail union boss Mick Lynch pleading with him to call off strikes and to not unleash a “devastating” impact hospitality. The heads of Fuller’s, Young’s, Drake & Morgan and the City Pub Company were among those appealing to the RMT leader today. This comes after union bosses announced on Tuesday that 40,000 of its members will walk out on 13, 14, 16, 17 December as well as 3, 4, 6, 7 January. This coincides with the hospitality and retail sector’s busiest trading period. Hospitality firms are also suffering beca…