The increase in rates has predominantly been fuelled by the spread of the highly transmissible ‘Delta’ Covid variant, which has now been detected in most parts of the country. Covid-19 cases overall increased in England by 28.4 per cent per 100,000 people in the week to 27 May, with some council areas seeing a surge in infections over the latest seven-day period. Listed are the 15 council areas which saw the biggest increase in coronavirus case rates in the week to 27 May. Council areas have been measured by the percentage change in cases over a seven day period. This means that while some areas have seen a huge percentage increase, they may still have a lower rate per 100,000 compared to other places. Images are for illustrative purposes only.