I work as a Junior Software and Games Programmer in the UK
we don't make commercial game as in we don't make our own games, instead we take on work from clients inside and outside of the UK, we make games for entertainment and serious games for learning, but we also make applications for mobiles using game mechanics (We made the GAME Retail Augmented Reality Scanner application).
There are many jobs in the UK for games development although due to tax reasons it is true many company have there main bases in Ireland but Unreal have just opened a new office here in England.
The biggest misconception with the games industry worldwide is people thinking that all the games are made by large companies, when over 70% of games are made from small indie companies and many of them are in the UK.
Although I have worked in the games industry for the past 2 years I will be leaving my job to go and get my degree (I am 19 in May) this year.
The one thing to realise is, is that America is a lot bigger than the UK, so there are so many more jobs in almost every field there, but the UK has enough, although I personally plan to open my own business after I finish my Degree/Masters(maybe).
From what I have found is that UK games companies require a lot of experience to get into, that is why I went straight into it at a young age learning to program when I was 13 and managed to get a job by the time I was 16 (almost 17), the best way to get into it in the UK is to simply have the skills they want, learn as much as you can, I personally found having Unity3D and C# programming skills to be a massive help.
As a side note, many people in the games industry work from home as well as freelance Programmers or Artists and work alongside companies in many different countries and I know of a few people who while doing this have ended up opening an office in the UK as a UK base for bigger american companies!