What are the Boris Files? Former PM's commercial interests in the spotlight

The Boris Files are a cache of leaked data from the Office of Boris Johnson, the former prime minister's private office.

- Paul Lewis, Pippa Crerar

The data shines a spotlight on Johnson's commercial interests since he left Downing Street in September 2022. It reveals how the former Conservative leader is using the relationships he forged in the UK's highest elected office to facilitate his personal enrichment. He appears to be doing so via his private office, which is subsidised by the public.

It raises a number of serious questions for the ex-PM. Has he broken "revolving door" rules that restrict post-ministerial jobs? Did he breach the ministerial code? Has he been misusing public funds for private gain?

The leak also contains documents from Johnson's time in office, raising questions about secret, undeclared meetings and potential breaches of Covid lockdown rules during the pandemic.

The Guardian is the only UK media organisation known to have viewed the Boris Files, and the first to have published stories based on the leak.

Where did the files come from? What do they contain? And how has the Guardian decided what should be made public?

Emails, invoices, spreadsheets

The Office of Boris Johnson is a limited company that takes advantage of a scheme that allows former prime ministers to claim a six-figure sum in annual expenses from the Cabinet Office. The money is for administrative and secretarial costs "arising from their special position in public life".

As leaks go, this one is relatively small: approximately 2GB of data, or 1,820 files. It includes emails, letters, invoices, spreadsheets, speeches and business contracts. These mostly postdate September 2022, when Johnson left office, but there are some files covering the entirety of his time in No 10.

The data was obtained by Distributed Denial of Secrets (DDoS), which archives data leaks. A US-registered non-profit committed to transparency, DDoS hosts a library of more than 360 data leaks online.