First thing to assess is the Power Steering fluid. More than likely you are low or empty and thus, the ability to be agile with the wheels has become difficult. secondly, if the first is not the problem, then i would assess the power steering pump. These do go out at about 45-60K miles on most American made cars. So, this could be the second thing to rule out. third is the rack and pinion, the steering column down to the axle and then out to the tires should be assessed for leaks, no compression, etc. Hopefully this helps you out.
worn bearings on steering column shaft inside steering column
You have to replace the ignition key cylinder.
Try moving the steering wheel left and right then attempt to turn the key.
try turning your steering wheel hard either way WHILE turning the key, sometimes the steering wheel locking mechanism interferes. you wont be able to turn your steering wheel like your actually turning, just move it and it should let the key turn
turn steering wheel to left tight while turning key
hopefully your not stealing the vehicle. but you will have to remove the steering wheel and then remove the key switch itself, purchase a new key switch and replace. However if its only to move the vehicle, after you remove the key switch you can take a screw driver and turn the mechanism in the column to unlock.
Maybe your steering wheel it's keeping the ignition cylinder to turn, so move the steering wheel and at the same time try to turn the key. Maybe you need to replace the ignition cylinder key lock
try rocking/turning the wheel while turning the key.
Try turning steering wheel slightly while you do it.
steering wheel in locked positon try moving it a little either way and the key should turn. The steering wheel has a locking device that wont let the key turn if the wheel is not free or you have the Wrong key
Step on brake first. Turn steering wheel slightly to remove tension on key.
Try turning the steering wheel whilst turning the key, most peugeots have a built in steering lock.
Your key could be worn. Try moving your steering wheel while turning the ignition. If the locked steering is in a bind the key will not turn over.
Try turning the steering wheel either to the right or left while attempting to turn the key
Put the key in and move the steering wheel until the key can turn
You could try turning your steering wheel both directions to release pressure then turn.
put the key in the ignition and turn the steering wheel and the key at the say time (turn the steering wheel to the left)
Try moving the steering wheel left and right then attempt to turn the key.
make sure the steering wheel isn't locked