Demand for places at high-achieving state schools across the UK far outstrips supply, turning the schools admissions process into a battleground. For many parents it has become one of the most stressful moments in their lives. The losers in this extraordinary educational lottery are often the locals - locked out of the best schools by people playing the system. Panorama goes to Havering to follow the council's campaign to clamp down on abuse of the system and follows the fortunes of parents who've applied for places in one of the most over-subscribed boroughs for primary school places in the country.