Thanks for the replies. As the OP, please let me reinterate that the ONLY question I had was on whether it is permissable in France to descent to the 25 mile MSA altitude when off airways/route but cleared direct to an iaf and cleared for approach.
Those who referenced "intermediate/check altitudes", "stepped descents", "platform altitudes", chart altiitudes", "minimum altitudes", "common sense", "mea", "altitude restrictions" unfortunately for me did not give me a clear answer.
My thanks for Intruder for at least coming forward and giving his answer, a definite NO.
Jeehell seems to say YES I can use the MSA once cleared approach.
Ast83 seems to say no.
PBL, yes, please ask your colleague for his input.
PantLoad, the TWA aircraft was well below any safe altitude. No one is suggesting that.