Backpacker.
In this situation I would perhaps be tempted to state your position in terms of position and miles to the VOR ( eg 10 miles east of xxx ) you are using for your navigation, as this gives London Info a fighting chance of, 1; knowing where you are and 2; knowing what your intended track is so that they can give you the best service they can.
The temptation is to over complicate things, where as the best solution is often the simplest.
Happy flying!!