A new three-tier lockdown system is under consideration for England, with the potential for harsher restrictions including the closure of pubs and restaurants.

The draft traffic-light-style plan, leaked to the Guardian, is designed to simplify the local restrictions, which apply to about a quarter of the UK.

Also including a ban on all social contact outside of household groups, the tougher measures could be imposed by the government locally or nationally if coronavirus cases are not brought under control.

Called the ‘Covid-19 Proposed Social Distancing Framework’ and dated 30 September, it has not yet been signed off by No 10.

The most serious alert level 3 includes the closure of hospitality and leisure businesses, as well as a ban on social contact outside households, restrictions on overnight stays away from home, and a halt to all organised non-professional sports or other communal hobby groups and activities, such as social clubs in community centres.

Places of worship can remain open. Schools are not mentioned in the draft, with Boris Johnson keen to ensure they are protected from closure.

A government source told The Guardian the measures in the draft document, particularly those under alert level 3, had not been finalised, and the document still needed to be approved by ministers in the covid-operations committee and by the prime minister.

The three-tier system is said to improve compliance with the rules: “Research tells us that people would welcome a clearer and simpler structure to the advice and rules that they should follow,” it says, acknowledging that “many people do not have a clear understanding of the rules that apply to them”.

The document says that alert level 3 would be “triggered in geographical areas or nationally when alert level 2 measures have not contained the spread of the virus, or where there has been a significant rise in transmission”.

Under alert level 2, people must not meet others outside of their household in private dwellings or gardens, apart from their support bubble, or in pubs, restaurants or other settings. Level 2 will be “triggered in geographical areas or nationally when there has been a rise in transmission, which cannot be contained through local responses”.

Alert level 1 contains restrictions currently in place across England, including the “rule of six” for gatherings indoor and out, the wearing of face-coverings, the 10pm curfew on hospitality businesses and numbers limited to 15 at weddings and 30 at funerals.

A Whitehall source said the levels were intended to be “minimum standards” and specific local circumstances would also be taken into account.

Downing Street declined to comment. A government source said it was an “early draft and proposals are still being considered by ministers”.