Today when I turned the key on, the starter did not engage and all the lights came on,accessories working but no start.
Then I tried again with the gear in Neutral, the car started without any problem. Again I tried the ignition with the gear in P, the starter would not engage.
Now it starts without any problem in N but not in P.
Is this something small that I can repair or is it going to be a big job.
Please help.

__________________
300CE 1989 Euro Model.
ML350 2011.