Edit: I just been reading the op posts/threads, lives in Wales likes cornies, replies to cornie thread but not much else...made a nice stout.....so I guess op makes 5 us gallons or there abouts

Not sure I understand your response. I said to mix wort and yeast, therefore the yeast does exist.
Looked to me like the OP was going to under-pitch quite significantly. An hour or two in wort before pitching is unlikely to promote much, if any, growth. It has the benefit of promoting a desirable yeast physiology, prepping them to ferment. That's all.
I’m aware of this. Was of the understanding that it had been established that the OP needed more viable yeast for the gravity of wort he was planning to ferment.