Counsel for the inquiry, Hugo Keith KC, said thousands of documents had been requested to inform the inquiry, and gave the Cabinet office as an example.
“We have sought agendas, minutes and other documents associated with the core decision-making forum such as Cabinet meetings, Cobra meetings and ministerial implementation groups,” he said.
“We've asked for ministerial submissions, Number 10 daily briefing documents, records of written and oral advice to ministers and details of internal communications including a WhatsApp group, which included the prime minister, Number 10 and other senior officials.”
Along with current UK Prime Minister Rishi Sunak, in April Mr Johnson was fined for breaking lockdown rules and has been accused of deliberately misleading parliament over the so-called “partygate” scandal that rocked the Tories at the beginning of the year.
Too late to lock down?
The scope of the Covid inquiry isn't just limited to lockdowns breaches by those in power, it also seeks to address whether those in power were too slow to implement these lockdowns.
Earlier, as he opened the second stage of the statutory inquiry, Mr Keith said the hearings would examine whether lives could have been saved by earlier lockdowns.
In his opening address, Mr Keith said the crisis placed “extraordinary levels of strain” on the UK's health, care, financial and educational systems and businesses, on top of individual bereavements.
He said its impact will be felt for “decades to come”, adding: “The pandemic has led to financial and economic turmoil.
“It has disrupted economies and education systems, and put unprecedented pressure on national health systems. Jobs and businesses have been destroyed and livelihoods taken away.
“The disease has caused widespread and long-term physical and mental illness, grief and untold misery.
“Its impact will be felt worldwide, including in the United Kingdom, for decades to come.”
Module two will scrutinise political decisions and actions in relation to the pandemic, covering a period between early January 2020 until February 2022, when the remaining Covid-19 restrictions were lifted.
Inquiry chairwoman Baroness Heather Hallett will examine the effectiveness of mandatory lockdowns in controlling the spread of coronavirus, the inquiry was told.
This will include “the relationship between the timeliness and the length of the lockdown, and the trajectory of the disease”, Mr Keith said.
He continued: “How were economic and societal impacts, including the impact on physical health, healthcare provision, mental health, education and societal well-being, assessed and weighed in the balance?
“And perhaps, my lady, the single most important question: is it possible to say what the likely effects of earlier or different decisions to intervene would have been? The counterfactual proposition.
“Bluntly, would lives have been saved if the lockdowns had been imposed earlier or differently?”
Mr Keith said questions would be asked about the role of the Scientific Advisory Group for Emergencies (Sage), including whether any lessons may be learned from the “structures in place in other countries for the provision of scientific advice to policymakers”.
“Was the system of government medical and scientific advisers effectively utilised? How effective was the decision-making system under which the prime minister and other ministers acted on the advice and recommendations of the relevant bodies and advisers? Did the system allow properly for timely political decision-making?”
Covid data accuracy evaluated
He said further questions would be asked about whether committees were working with relevant and accurate data.
“How effectively was data distributed through the government? How reliable was the infectious disease data modelling? Did the data modelling cover the right eventualities? Was there an over-reliance on epidemiological modelling or mathematical modelling? Was there an over-reliance on influenza epidemiology and data modelling?”
About 200 scientists, including all those involved in the Sage group and others in the Independent Sage group, have been asked to give evidence about the effectiveness of the pandemic response.
The probe also heard that 39 individuals, groups and institutions have been granted core participant status for the second module.
These are individuals, organisations or institutions with a specific interest in the inquiry who can access relevant evidence, make opening and closing statements and suggest lines of questioning to inquiry counsel.
Mr Keith said the pandemic “reached out and affected almost every person” but its impact was not equally felt.
He welcomed the inclusion of bodies representing children, older people, disabled people, domestic abuse victims, those with chronic mental and physical health needs, members of ethnic minority communities and people with long Covid.
A further preliminary hearing for the module will take place in early 2023, with public hearings starting in the summer. These are scheduled to last for about eight weeks.