As has been correctly said UK and European PAL are different formats. The picture is the same but the sound is on different frequencies I believe.
In the end the only way I was able to get my Atari games console to work was to find an old TV on eBay, in this case a KDL-15G2000, which had the right tuner options. It also had the key capability to change which sound format it used (including to European PAL), this meant I could change it to be fully configured to work with my German Atari 2600. Thus I was able to get both picture and sound.