Most likely on your car the remote does all the work and the key is just normal so you can just get another one cut anywhere.
The remotes cost about �30 and have to be coded by a diagnostic machine (probably at extra charge).
You could just go for cutting a new spare key and asking a Rover garage (there are still a few around) to look up the cars "key access" number, this allows you to de-immobilise the car using only the key. So you can use the remote you have and use the Key only technique in an emergency.