you should be relatively young, still in your mid 20s if you are female and late 20s if you are male. you could consider working in office roles for unis, but doubt they will consider you as having the experience.

in a non-education role you will have to start out at the bottom. i think you have to realistically expect a big pay cut from cushy civil service jobs.

just to encourage you, i know of an ex-colleague who came from teaching. he joined a GLC in a generalist executive position in his early 30s and he's doing pretty well for himself now in the corporate world in his late 30s.

all the best!