Thanks for your replies. I can't get a French State pension as the qualifying years are now minimum 10, and I only did 5.
The Agirc/Arcco pension can be claimed at 62 if you have the qualifying years for a full state pension. If not then you wait until 65. Or 67 (nobody can tell me for sure). I filled out the form to create an Argirc/Arrco account, but because of a 'technical error' I have to call a pensions advisor. However I have just found this on the website :-
If you live in a country of the European Economic Area* or in
Switzerland: your pension application must be submitted to the
pension institution of the State of your residence. The file compiled is
sent to the French basic pension scheme, which sends a copy to
Agirc and Arrco. The "European Coordination" service of Agirc and
Arrco registers your request for supplementary pension. You will
receive by mail a file to complete and return. Upon receipt, this file is
sent to your Arrco fund and, if applicable, to your Agirc fund, for study
of your rights.
So after all this, it looks like HMRC might be my first point of call..............