The problem was post-2016 the Tory party, rather than deciding to find a solution which worked for everyone (or at least one most people could stomach, which was probably EFTA), went full batshit nativist (at least the fringe did) and ended up demanding a ridiculous scenario of walking away...
Point of order, referendums are mandatory when they relate to voting people into the Commons. So the AV referendum in 2012(?) was mandatory, but none of the others have been.
I dislike this comparison. Far be it from me to defend Moseley, but he was (by all accounts) intelligent, charming and erudite. I don't believe Lee could even spell those traits, never mind display them.