Ignition help

Right this morning I got to work as normal turned the key and switched the ml off but I could not get the key out:confused:I left it all day because we had a comp but come 5ish I tried to start the car with no joy like the barrel has ceased up and I could not get it going.I got green flag out and he was trying for 30 mins
In the end I did jiggle it and got it started but every time I start it I have to jiggle it,

Please help me because I need to get it sorted
Cheers Stewart