Fracking in the UK: what is it and why is it controversial?

As Cuadrilla starts operations in Lancashire, we examine the main argumentsFracking protesters blockade Lancashire site as work beginsFracking restarted in the UK on Monday - the first such operation since 2011. The oil and gas firm Cuadrilla is preparing to commence operations at a well in Lancashire, after seeing off a last-minute legal challenge.The aim is to extract shale gas to contribute to the country's energy supply, but environmental campaigners fiercely oppose it. Continue reading...