Ignition switches are common failures on the K12, so much so that Nissan replacement starter motors normaly are supplied with instructions to replace ign. sw. before replacing starter motor.
Quote: "17-9-2013: 2005 Micra needed new starter motor, cost £278. Apparently requires a new ignition switch to be fitted at the same time, total cost £539. Begs the question why this was not fitted the first time".