Will it be the rapidly disappearing former garden favourite, the small tortoiseshell? Or the poet John Masefield’s “oakwood haunting thing” , the charismatic purple emperor? Or perhaps the brimstone, the ultimate harbinger of spring ? The question of which is Britain’s favourite butterfly is being put to a popular vote for the first time. The charity Butterfly Conservation is running the poll, which runs until 7 June, giving people the chance to choose their favourite from the 60 species that fly around Britain every summer. Julie Williams, the chief executive of Butterfly Conservation, said: “It’s clear Britain is a nation of butterfly lovers. From Sir David Attenborough and the royal family to the hundreds of thousands of people who have taken part in Butterfly Conservation’s Big Butterfly Count , these incredible insects hold a very special place in our hearts. “ Now, for the first time ever, we want to find out which of our much-loved butterflies takes the nation’s top spot.…