LONDON (Reuters) -The acquisition of Britain’s biggest microchip factory Newport Wafer Fab by Chinese-owned technology company Nexperia has been called in for a full national security assessment, Business Secretary Kwasi Kwarteng said on Wednesday. “We welcome overseas investment, but it must not threaten Britain’s national security,” Kwarteng said on Twitter. Prime Minister Boris Johnson said last year he did not want to drive Chinese investment away from Britain because of “anti-China spirit”, when asked whether the sale of the semiconductor producer would go ahead. [nS8N2NF065] The governme…