And they would not have been able to run with some of the arguments they have used - for example, the immigration argument would have had to be put far more carefully and while making less extreme claims if the FLEXCIT plan were being followed.
(Mind you, with a lot of floating voters that might not have been as big a negative as much of UKIP and other hardliners appear to think)
However, if Leave were putting forward a clear plan, they would not be as vulnerable to attacks like the poster and tweet below both of which appeared on Twitter today.
I still think this referendum is going to be close and could yet go either way. But both the official Leave campaign, and their rivals at Leave.EU, appear to be doing their best to blow it.