Ministers have written to the City of London demanding it stop people from swimming in a protected pond on Hampstead Heath, after disturbing scenes of cygnets and eggs being disrupted went viral on social media. Swans and their 12-day-old cygnets were disturbed by hordes of splashing revellers in the north London park on Monday as temperatures reached a record 35C in the capital. In one video, a swan was seen poking an unhatched egg with its beak after it fell into the water during the chaos. Conservationists responded with dismay after a video was shared on social media of the scenes which the the City of London, the local authority that owns Hampstead Heath, called “utterly appalling”. Coots, moorhens and swans were seen guarding their eggs and young as people obliviously splashed around them. There are large signs around the pond urging people not to swim as it is a wildlife conservation area.…