<ul><li><a href=http://www.legislation.gov.uk/ukpga/2011/5 target=_blank>Postal Services Act 2011(last updated in April 2017, Part 3:  Section 38)</a></li><li><a href=http://www.legislation.gov.uk/ukpga/1998/41/contents target=_blank>Competition Act 1998(last updated in June 2017, Sections 4 - 11    )</a></li></ul>