I don't have an IFR chart immediately to hand, but, if I remember correctly, isn't the entire area between Cherbourg Zone and Rennes Zone criss-crossed with Airways from about FL50 upwards?
My IFR map indicates that there is a criss cross of ATS routes, you are definitely right. But to the best of my interpretations they do not appear to be a classed airspace. Perhaps someone can enlighten us? To the best of my (perhaps poor?) understanding the class D airspace on my route started at FL115, and whilst there are lower level ATS routes they are not "controlled" classed airspace.
Either way - during my trip I was in contact with ATC at all times, and it didn't appear that I was within controlled airspace even if I was (no clearance, no headings, no requests, just the weird statement posted above).
Foxmoth! You almost had me thinking that I needed to re-review the privileges of my license... I was absolutely sure that I was not allowed to do that! But anyhow - soon I hope to be fully IR qualified! :-)
best.
alex