[moises]

Hi Jonathan,
You might also (if you haven't done so already) want to check exactly what Credit Agricole's position would be - I work for an estate agents and have had clients doing similar things, but the bank may still take the UK mortgage into account on the debit side and not be keen to take a temporary rent into account on the credit side, if you see what I mean. Though this might be academic depending on your general income anyway.
Have you also considered a bridging loan ("pret relais" in French)? Our local CA offers a 2 year deal which is not bad as far as I can tell.
See you soon