Having lost my job just before Christmas last year, I can from experience state this is the worst time possible. It is so frustrating to be chasing a new job when everyone else is winding down for Christmas and does not really want to know. All you hear is 'we'll be looking at that in January', and nothing really moves from the beginning of December until Jan 10th. I was lucky enough to land another job in January, but it made for a depressing Christmas. There is no good time to lose a job, but at least after Christmas means you can crack on with job hunting straight away.
Good luck to all involved.