(Reuters) – More than 70,000 staff from British universities have voted to strike in a dispute over pay, a trade union in further and higher education representing academics and support staff said on Monday. The University and College Union (UCU) said it now has a mandate to deliver strike action at practically every university in the UK. The latest announcement adds to growing industrial unrest across Britain, with rail workers, health staff and legal professionals striking or planning strikes to demand better pay and conditions. UCU said the staff voted across two separate ballots, one for p…