LONDON (Reuters) -More than 40,000 British workers for telecoms company BT Group will hold a two-day national strike over pay on July 29 and Aug. 1, their first such action in 35 years, the Communication Workers Union (CWU) said on Friday. “The reason for the strike is simple: workers will not accept a massive deterioration in their living standards,” CWU General Secretary Dave Ward said. The union previously said the strike would delay broadband rollout and may disrupt phone and internet users, including those working from home. BT Group said it was not prepared to improve its offer of a flat…