The coronavirus restrictions extension and revisions to them, announced for England, yesterday 14 June 2021, have been reflected in legislation made and laid before Parliament this morning and due to come into force at 11.55pm on 20 June 2021. The government has issued an explanatory note on the changes. This you will find at https://www.legislation.gov.uk/uksi/2021/705/pdfs/uksiem_20210705_en.pdf
If you want chapter and verse, feast yourself on the Health Protection (Coronavirus Restrictions) (Steps and Other Provisions) (England) (Amendment) (No 2) Regulations 2021 (SI 2021/705) - swinging title, eh? - which those of you who want to cool off will discover at https://www.legislation.gov.uk/uksi/2021/705/pdfs/uksi_20210705_en.pdf