The good news first, you can drive for the first 3 months on your Philippines license. The bad news is that you will need to take a new test (well three tests actually).
I would highly recommend getting some lessons regardless. Driving in the UK is much, much faster then you'll have been used to and failure to comply with UK driving rules will put you into a sticky situation.
As an example, when my missus first drove in the UK, she attempted to 'nudge' out into the traffic, if she hadn't been with an instructor with dual controls, then she would have had an accident as the car coming towards her would probably have not been able to stop in time.
You will also need to buy a computer program which will help you learn the rules and get ready for the theory and test thing with a video. You can buy the software from the likes of HMV and Game for around 9.99 and driving lessons will cost around 14 - 20 pounds per hour. If your like my other half, around 8 hours of lessons will be more then enough to adjust to the British way of driving.
Hope this helps.
