The Institute for Advanced Legal Studies launched their short report on whistleblower and source protection in the House of Lords yesterday: http://ials.sas.ac.uk/research/research-centres/information-law-policy-centre/research/journalists%E2%80%99-sources-surveillance

The Guardian, which supported the research, has covered it here: https://www.theguardian.com/media/2017/feb/22/whistleblowers-need-greater-protection-digital-age-media-lawyers-say

Includes a response from Government along the lines of nothing to worry about, trust us.