Fiesta mk3 ignition key problems

I recently bought this second hand ford fiesta, it came with the red master key and a spare and the lock key. The problem is that it is very hard to actually turn the key and start up the car. It turns a bit (to position I as its called in the maual i think) but then it's really stiff and you have to try for about 30 seconds before it turns to position II (where the dashboard lights & everything comes on). This is quite bad with the master key and its even worse with the spare. What should i do? Is there any point tryin getting another copy of the master key?

try some wd40 down the barrel