Covid inquiry: What is it investigating and how will it work?

The first public hearing organised by the inquiry into the government's handling of the coronavirus pandemic has begun.

The government is challenging the inquiry's request to see some messages sent between former Prime Minister Boris Johnson and colleagues.

Public inquiries respond to "public concern" about events. Established and funded by government, they are led by an independent chair.

An inquiry has the power to make people appear as witnesses and can demand evidence.

No one is found guilty or innocent but conclusions about lessons learned are published. Inquiries can make recommendations although these do not have to be adopted by ministers.

The Covid inquiry, launched by Boris Johnson in May 2021, is investigating the government's handling of the pandemic, and covers decision-making in Westminster and the devolved administrations.

At the time, Mr Johnson said all aspects of the UK's response would be "under the microscope".

It is being chaired by Baroness Heather Hallett, a retired judge and crossbench peer.

She previously led the inquests into the 7/7 London bombings.

The inquiry has no formal deadline but is due to hold public hearings across the UK until at least 2025.

At the first public hearing in London, Baroness Hallett said she planned to publish updates and reports "as we go along" on the inquiry's website.

Public hearings are streamed on the inquiry's YouTube channel, and witness transcripts will be published on its website.

Members of the public can apply to attend public hearings in person.

Work in four areas has already begun:

Future strands - with hearings due in 2024 and 2025 - will look at:

Scotland is also holding a separate inquiry.

Baroness Hallett's team is expected to focus on the biggest and most controversial aspects of the government's response, including:

The inquiry is also expected to consider whether too many restrictions were imposed as the pandemic progressed.

Over the course of 80 days in autumn 2020, for example, England went from the so-called "rule of six" to a tiered system of regulations, then into a national lockdown and then back to tiers.

The government's policy towards schools is also likely to be on the agenda. Schools closed to most pupils in March 2020 and then again in January 2021.

Although a full list of witnesses has not yet been published, senior government ministers and officials are expected to give evidence under oath.

Sir Chris Whitty, the UK government's chief medical adviser during the pandemic, and Sir Patrick Vallance, the chief scientific adviser, are likely to appear.

The inquiry will also hear from independent health, scientific and policy experts.

Members of the public have been invited to share their experiences through the inquiry's Every Story Matters project.

The Covid-19 Bereaved Families for Justice campaign group - which has been critical of the government's handling of the pandemic - has urged the inquiry to ensure these voices are heard.

The inquiry asked to see unredacted WhatsApp messages between Boris Johnson and 40 people.

They include former No 10 adviser Dominic Cummings, Cabinet Secretary Simon Case and former chancellor and current Prime Minister Rishi Sunak.

The Cabinet Office launched a legal challenge against the request, arguing some of the messages were irrelevant. This is thought to be the first time a government has taken legal action against its own public inquiry.

Baroness Hallett said it was her job to decide if material was relevant.

However Mr Johnson said he was "perfectly content" for the inquiry to have WhatsApp messages sent after May 2021. He said earlier messages were not available because his mobile phone was involved in a security breach and had not been used since.

Former Health Secretary Matt Hancock also said he was happy to share his messages, although many of these have already been leaked by the journalist Isabel Oakeshott, who helped Mr Hancock write his book, Pandemic Diaries.