Peugeot 406 hdi ignitionkey jammed in barrel?

Peugeot 406 hdi 90bhp w reg (2000)
my much loved friend ,pushing 300k , still running as economically as ever (61.4mpg) threw a new one at me today, i tried to turn it off and the key wouldn't budge, wiggling it seemed to effect the fan, and the whole mechanism feels a bit sloppy. I'm loathed to give up on the old girl just yet... any suggestions please?