Quoth AC Grayling, writing in The New European in October:
This is a key matter. If the 2015 Bill been expressly offered as binding Parliament and Government to the referendum outcome, there would have been discussion of the need for a minimum threshold vote. Briefing Paper 07212 expressly alerts MPs and members of the House of Lords to the fact that 'major constitutional change is something more important than the result of ordinary elections, and therefore should be the outcome of something more than a simple plurality of votes.' (§6, p 26). No threshold was specified in the Bill, because the intention was that the referendum was advisory only. (Full text)
Did MPs want a significantly higher threshold than 50% when the bill was debated? Did anyone specifically go on the record favoring a 50% threshold (against this briefing paper) during the debate?