Well it's not going to make any difference is it seen as both the government and the opposition aren't pursuing rejoining so much as the SM and CU anytime soon .
Besides if that was the case why didn't they invite a Lib Dem on who is currently in parliament ?
Everyone knows Campbell , New Labour and the present Labour Party are massively pro EU and he's unlikely to say anything that he hasn't said before .
It doesn't much matter what he says does it in the grand scheme of things .
That said he's bang right that anyone who served in the Johnson cabinet and defended the indefensible up until last week shouldn't be anywhere near getting the top job in the country .