Teachers at a school which has been at the centre of a parent-led campaign against plans to hand it to an academy trust are to hold four days of strikes beginning next week. Industrial action at Waltham Holy Cross primary in Waltham Abbey, Essex, was announced as it emerged that the incoming trust, NET Academies, had been referred to the government’s Standards and Testing Agency (STA) over concerns about the administration of recent Sats testing of six- and seven-year-olds at…