No, not acceptable for me. Corbyn was remain in the buildup to the referendum, and should have used that and campaigned. Instead he sat back and did nothing. A potential leader should demonstrate leadership skills, not sit back and wait for things to happen around him. Although I will say his position, or lack of, is still more favourable than that of Johnson, who is nothing more than an opportunistic hypocrite. As much as I don't want Johnson to be PM, Corbyn is just as inept (albeit for different, less odeous, reasons).