In June 2020, the BBC Shared Data Unit and BBC Data Unit reported some of the largest UK councils said they might have to declare themselves effectively bankrupt unless the government agreed to further support.

The in-depth investigation necessitated contacting 216 upper tier council authorities across the UK for details of their current and forecast financial position, including whether or not they would meet the criteria to issue a section 114 notice - effective bankruptcy.

Five councils said section 114 emergency spending controls could be needed due to the impact of Covid-19. Liverpool, Birmingham and several other councils outlined the need for an emergency or in-year budget.

Nearly 150 authorities forecasted a combined budget shortfall of at least £3.2bn.

It followed a report in May from the SDU on warnings the emergency funding allocated to councils would not be sufficient.

This project was completed with help from the Local Democracy Reporting Service, reporters who focus on local council matters. The LDRS is part of the Local News Partnerships alongside the Shared Data Unit.

The Shared Data Unit makes data journalism available to news organisations across the media industry, as part of a partnership between the BBC and the News Media Association. Stories generated by the partnership included:

• Berkshire Live: UK councils fear they will have to declare themselves bankrupt unless the government provides more coronavirus support 25 June 2020
• Birmingham Mail: Government is 'working on a plan' to stop local authorities going bankrupt 25 June 2020
• Bolton News: The multi-million cost of fighting cornavirus 25 June 2020
• Bucks Herald: Could coronavirus bankrupt our council? Bucks chiefs say it is hard to predict the scale of the crisis, but that frontline services will be protected as a priority 25 June 2020
• Bury Free Press: Labour fear Suffolk County Council could make cuts to compensate Covid-19 losses 26 June 2020
• Cambridgeshire Live: UK councils fear they will have to declare themselves bankrupt unless the government provides more coronavirus support 25 June 2020
• Cornish Stuff: Could Covid-19 bankrupt councils? 25 June 2020
• Eastern Daily Press: ‘A pack of cards about to collapse’- dire warning over money for councils 25 June 2020
• Edinburgh Evening News: Covid-19 predicted to cost £159 per person as Edinburgh's finances suffer 25 June 2020
• Epping Forest Guardian: Coronavirus leaves Essex County Council facing huge deficit 26 June 2020
• Ham & High: Barnet Council doesn’t rule out ‘bankruptcy’ if government support for Covid-19 expenses fails to materialise 26 June 2020
• Hemel Today: Hertfordshire County Council predicting £17million shortfall due to COVID-19 25 June 2020
• Hillingdon & Uxbridge Times: Hertfordshire County Council predicted to have funding shortfall 25 June 2020
• Hull Daily Mail: UK councils fear they will have to declare themselves bankrupt unless the government provides more coronavirus support 25 June 2020
• The Independent: Coronavirus: UK towns and cities warn of potential bankruptcy due to pandemic 25 June 2020
• Inverness Courier: Highland Council faces a shortfall of £96.9 million – £411 for every resident – in lost revenue due to the coronavirus lockdown 25 June 2020
• InYourArea: The UK councils facing potential 'bankruptcy' as coronavirus pandemic takes huge toll on public finances 25 June 2020
• Islington Tribune: Town Hall leader: It’s tight but we won’t go bust 26 June 2020
• ITV: Wiltshire Council warns it could face bankruptcy unless it gets more help from the Government also: Essex County Council predicts shortfall of £14m due to coronavirus crisis 25 June 2020
• Lancashire Telegraph: Services could be hit as £64 MILLION cost of coronavirus hits councils 25 June 2020
• Lincolnshire Live: Councils lose BILLIONS in pandemic - here's how Lincolnshire is affected 25 June 2020
• Liverpool Echo: Merseyside council faces £27m black hole due to 'devastating' impact of coronavirus 25 June 2020
• Mail Online: Councils beg Government for more cash to stave off bankruptcy as Manchester faces £166m loss and Wiltshire needs an extra £51m due to Covid crisis 25 June 2020
• Maldon Standard: Covid-19 leaves Essex County Council with £171m shortfall 5 July 2020
• Manchester Evening News: Two more Greater Manchester councils warn they may soon become bankrupt due to Covid-19 25 June 2020
• Mid Devon Advertiser: 'Rainy day fund' means Devon's finances 'not in a bad position' from coronavirus crisis 27 June 2020
• Nantwich News: Councils like Cheshire East face massive budget shortfalls, stats show 25 June 2020
• Oxford Mail: Oxfordshire's councils and Covid: How much money trouble are they facing? 26 June 2020
• Peak FM: Council in danger of scrapping non-essential services if it doesn't receive government funding 25 June 2020
• Peterborough Matters: Coronavirus: Councils will not be bankrupted - but want government help 25 June 2020
• Quest Media Network: Is your council at risk of banruptcy due to Covid-19? 25 June 2020
• Rochdale Online: Rochdale Council faces £28.1m funding shortfall due to Covid-19 25 June 2020
• Ross-shire Journal: Covid-19 coronavirus lockdown leaves Highland Council facing a shortfall of £96.9 million – £411 for every resident – in lost revenue 25 June 2020
• Rutland and Stamford Mercury: Lincolnshire County Council and Rutland County Council left millions of pounds short because of Covid-19 but they won't go bankrupt 25 June 2020
• The Herald: Councils funding shortfall reaches millions 26 June 2020
• The Scotsman: Scottish councils facing 'devastating' £400 million coronavirus financial black hole 25 June 2020
• Saffron Walden Reporter: County Council faces huge budget deficit without government support 28 June 2020
• Sheffield Star: Sheffield Council faces a £16m deficit dealing with coronavirus 23 June 2020
• Southern Daily Echo: Hampshire council tax payers facing a massive £190m coronavirus bill 26 June 2020
• St Helens Star: St Helens Council pushes on with emergency budget 25 June 2020
• The Telegraph: Councils call for Government to provide more cash as they risk going bankrupt 25 June 2020
• Wales Online: UK councils fear they will have to declare themselves bankrupt unless the government provides more coronavirus support 25 June 2020
• Watford Observer: Hertfordshire County Council predicted to have funding shortfall 25 June 2020
• Wiltshire Gazette and Herald: Wiltshire Council fears bankruptcy due to coronavirus 25 June 2020
• Wigan Today: Wigan Council faces £40m shortfall from Covid-19 25 June 2020
• Yellow Advertiser: Councils facing huge budget deficit 25 June 2020
• Yorkshire Live: This is how much Covid-19 could cost Kirklees council 25 June 2020
• Your Harlow: Essex County Council faces huge budget deficit 25 June 2020

The story was also used by the BBC News at One, Six and Ten, four breakfast television programmes, and 18:30 programmes for Midlands Today, Look East (West Edition Cambs), Look North Leeds, Look North Newcastle, Look North Hull, South Today Oxford, South Today, South East Today, Northwest Tonight, Reporting Scotland, Spotlight (Plymouth TV), Salford TV, Oxford TV, Birmingham TV. It also led the Sunday Politics England show. For radio, it led bulletins on the BBC Radio 4 Today programme, Radio 2, Radio 4, 5Live, including two-ways on least eight local radio stations: Wiltshire, Shropshire, Kent, Sheffield, Lancashire, Leicester, Merseyside and Cambridge while the report was featured on most other regional BBC radio stations. Online, it was promoted as the lead on the bbc.co.uk Homepage. It also had a separate lead on BBC Scotland.

• UK councils' data

• A full briefing pack on the story can be found here

• Bar chart: The largest shortfalls forecasted by UK councils as a result of the pandemic
• Bar chart: Councils' worst-case potential shortfalls per resident in £s

We have also looked at council finances in the following stories:

• 2019: English councils warned about 'running out' of reserve cash
• 2021: Pandemic leaves councils with £3bn black hole

You can find all coronavirus-related stories by the BBC data units tagged 'coronavirus' here