Very prescient article as it now turns out May used exactly this example in her meeting with Junker last week. Junker quickly shut her down saying I’m sorry but that will not work.
The opt outs which Britain gains over the years tended to develop as a group and then the majority of other countries wanted to do something new. So Social Chapter was new Major opted out, Blair opted in, Euro and Schengen we opted out as well as the. JHA example. The point is we were still a full member and without allowing an opt out we could have stopped or disrupted the other countries moving forwards.
This time once we are out we are out, we no longer have any influence on the internal developments of the union. They no longer have any interest in allowing us to opt back in.