Labor is calling for a ‘widespread’ investigation into ministers’ use of private emails to conduct government business amid allegations that former health secretary Matt Hancock used his personal account.

Despite his dramatic resignation from cabinet over the weekend, Labor has added to growing questions over Mr Hancock’s conduct in government, warning that vital information may have been concealed due to the use of an account Private Gmail.

According to reports, leaked minutes from a December meeting at the Department of Health and Social Care (DHSC) showed that Mr Hancock had been using an unofficial account since the start of the pandemic in March 2020.

The Sunday Times said the minutes revealed David Williams – then the department’s second permanent secretary – warned that the former cabinet minister ‘only’ dealt with his private office ‘through a Gmail account’.

The newspaper adds that the senior official said: “The SOS [secretary of state] does not have a DHSC inbox”, and also claimed that the Minister of Health, Lord Bethell, “regularly uses his private inbox”, but that official accounts were subsequently provided.

He said he ‘does not believe there was any improper action by ministers but can clearly see that the optics suggest otherwise’.

Cabinet Office guidelines state that if personal accounts are used for government business, the sender or recipient should “take steps to ensure that the relevant information is accessible (for example by copying it to an email address). -government mail)” for record keeping purposes.

In a statement on Sunday, a spokesman for the Department of Health and Social Care said: “All DHSC Ministers understand the rules around the use of personal emails and only conduct business through the their department’s email address.”

But calling for a wider inquiry into the matter, Angela Rayner, deputy Labor leader, insisted: “The blame does not end with Hancock and this case is not closed. This government is rotten to the core.

“We need to know how far this goes and how much government business is done in secret,” she added.

‘This sleazy practice has the potential to conceal vital information about the public waste of taxpayers’ money which has been given to friends of Tory ministers.’

In a letter to cabinet secretary Simon Case – the government’s top civil servant – Ms Rayner said the use of private emails would hamper the review of ministerial decisions, citing both the impact on requests for freedom of information and any future public inquiry.

“There is also a clear security risk if ministers use private email accounts to discuss government business, resulting in sensitive information being leaked or ministers being blackmailed by hostile actors.”

Ms Rayner asked the Cabinet Secretary to clarify whether the use of private emails could potentially violate the Official Secrets Act, the Freedom of Information Act, the Data Protection Act or the Privacy Act. public records.

And she demanded to know what steps were being taken by the Government to secure the emails of Mr Hancock and Health Minister Lord Bethell so they could be used as evidence in the Covid public inquiry, which is expected to begin next spring.

The deputy leader also urged the government to disclose if any ministers had used private email accounts in the award of government contracts during the pandemic.

A Cabinet Office spokesperson said: ‘We have received the letter and will respond in due course.

Elsewhere, Cabinet Secretary Brandon Lewis has also announced the launch of an internal investigation at the Department of Health and Social Care (DHSC) into how footage was leaked of Mr Hancock kissing an aide in his private office .

The Northern Ireland Secretary said Sky News the government needed to ‘understand exactly how it got recorded and how it got out of the system’, stressing that it was an issue ‘that we need to get to the bottom of’ because of the sensitive work of the ministries.