Thank you all very much for your concern and comments.
I don't think I'd ever grass-her to the BoE. It would be something I'd use in extremis, I'd have to have a very long bath after doing it... "Out damned spot" LOL.
There is a better way my remarkably beautiful intellegent and wonderful girlfriend came up with, which, as with most great ideas, is rather simple.
One of me ex's quirks is her hate of me being anywhere near the house (which I paid for LOL). She actually refuses to let me pick the kids up from the house, although she has no cause to, and instead drops them off. Part of this is she thinks I don't know she's building an extension whilst pleading poverty, but most of it is because she is, as previously mentioned, a neurotic bitch.
I'm simply going to inform her I want her threats to stop, and for her unreasonable restriction of access in holidays to end.
If she goes ahead with her threats, or continues to deny me access in the holidays, then she will find me and my girlfriend move back to the UK and move into a house in the same village as her.
And it would be no bluff. Our intentions are to move to the UK anyway, albeit not straight away.
I'm not being a typical ex-husband slagging off my ex-wife's sanity here; she really is boardline la-la land, and despite several years of looking has yet to find a permenant job, actually being passed over for permenant positions whilst a long-term supply teacher. She stopped using her child-minder because her child-minder told her she was being unreasonable (toward me). She bounced around several local Congs before becoming inactive, was warned off the late-teenage son of a local elder - she'd have been 45 at the time.
Huh, if only I had let someone warn her off me when I was late-teenage son of an elder...
But anyway, I gauge this idea will be horrifying to her and make her behave better. She doesn't even have to be nice, I just what my kids want and what is my legal right.