I work at a quite big company on a very big C# project, I have been here 12 months and this is my first real programming job. When I started I was on £23,000, but last November my manager called me in and explained I will be given regular wage increments over the next 18 months, which will take my salary up to £30,000 (this wasn't asked for, nor was it a discussion or a real negotiation, it was a 'this is what's happening' talk).
I was, at the time, very happy with this. Recently however another company offering £40,000+ has approached me, and they do seem like a good company too. My current job is a good one, it has some problems but (ignoring the money) I would prefer to stay where I am for now. This jump in salary is significant though, and I don’t want to wait another year and a bit to only be on £30,000.
It seems like I should just talk to my current boss, but I don't want to seem ungrateful and force myself out of the company, or seem like I'm giving ultimatums.
What should I do about getting a raise at my current job? Is it unlikely to happen now that I’ve accepted the current increment? Should I try to get a firm offer and numbers with this new company first?