Lock in tow bar loose

Can anyone confirm or otherwise if I have a problem or not. I have a 2007 disco 3 which I have had from new which has a lock in tow bar. Recently I noticed, although it could have been like this from new, that the tow bar can be manually moved slightly in the socket. A mechanic friend, not land rover, said it was ok as there was no way it could come out of the socket but as I am about to tow a largish boat 800 miles in October I am a bit concerned. I cannot get to a land rover dealer before leaving ( i am in the middle of france miles from anywhere) so am considering having it welded in the socket. If you have a similar age disco with a tow bar I would appreciate your reply after checking your bar. If you have any knowledge on the subject your reply would also be appreciated.