This newt is an Alpine newt, and the nominate form aswell... Mesotriton (formerly Triturus) alpestris alpestris, as can be told by appearance and throat. This species originates from western Europe. Nice find in some ways but not native to the UK.
Available soon CB 2015 - Salamandra.s.terrestris, Triturus marmoratus, Triturus.a.apuanus and nominate alpestris, plus plenty of Axolotls (leucistic, wild type, golden albino, albino and melanoid). Plenty more species of amphibian available summer 2015 - tropical, sub tropical, and also many temperate species suitable for secure outdoor vivaria.