The UK voltage is now 230 V +10% /- 6%, AC, 50 Hz. However, it's worth noting that this 'new' nominal voltage has been nothing more than a 'paper exercise' to comply with European harmonisation...
From Wikipedia's listing under the "war of currents" (http://en.wikipedia.org/wiki/War_of_Currents):
In the alternating current system, a transformer was used between the (relatively) high voltage...