Lord Salisbury is the Chairman of the Constitution Reform Group (CRG), a cross-party pressure group which seeks a new constitutional settlement in the UK by way of a new Act of Union. The group introduced the Act of Union Bill 2017-19 as a Private Member's Bill by Lord Lisvane in the House of Lords on 9 October 2018, when it received a formal first reading; its passage through Parliament was terminated by the ending of the parliamentary session in October 2019.
