The Civil Partnerships, Marriages and Deaths (Registration, etc) Act 2019 received Royal Assent on 26th March and will come into effect on 26th May this year.
Section 2 of the Act, requires the Secretary of State to ensure that regulations to amend the 2004 Civil Partnerships Act are in place by 31st December 2019. So, from next year, heterosexual couples should be able to form a civil partnership in England and Wales.
The full text of the Act can be found at: http://www.legislation.gov.uk/ukpga/2019/12/contents/enacted
(Source: Parliament.uk, 26th March 2019)