Demands for Paula Vennells, who was the company's chief executive from 2012 to 2019, to have her honour removed have re-emerged after ITV aired a new drama detailing how former sub-postmasters and sub-postmistresses were held liable by the Post Office for financial discrepancies thrown up by its computerised accounting system.

Hundreds were taken to court, left bankrupt, or imprisoned over the faulty Horizon system, developed by Fujitsu.

Ms Vennells has previously said she is "truly sorry" for the "suffering" caused to sub-postmasters who were wrongly convicted of offences.

But can her CBE be removed? Has it been done before, and does the King get involved? Here's what you need to know about the process.

How do you get a CBE?

Someone has to nominate you for an honour or award in the UK.

They can't nominate you specifically for a CBE, they can only put you forward for a general honour.

A committee made up of senior civil servants and people who are independent of government then decide whether you are worthy of any honours.

Anyone who receives one must be deemed to have:

• Made achievements in public life
• Committed themselves to serving and helping Britain.

To earn a CBE - Commander of the Order of the British Empire - the person needs to have played a "prominent but lesser role at national level, or a leading role at regional level".

You can also be awarded one for a "distinguished, innovative contribution to any area".

Ms Vennells got hers in 2019 for "services to the Post Office and to charity".

Can a CBE be taken away?

Yes, in an act known as "forfeiture".

This happens when someone who has received a CBE or similar honour has done something to "damage the honour system's reputation".

Reasons for an honour being withdrawn can range.

It could be something as clear-cut as the recipient being found guilty of a criminal offence, or because they've conducted themselves in a way that results in criticism from a regulatory or professional body.

But the government says it could be "any other behaviour that is deemed to bring the honours system into disrepute".

The honour can be forfeited irrespective of whether the behaviour leading to the decision occurred before or after it was presented to the recipient.

Who decides whether a CBE should be taken away?

Ultimately, the King does.

While the sovereign doesn't suggest forfeitures - that's down to the Honours Forfeiture Committee - it's the King who makes the final call, as he must give his approval before the honour is removed.

The committee is chaired by Sir Chris Wormald KCB, and consists of the treasury solicitor and four permanent, independent members.

Read more on this story:
Rishi Sunak adds to pressure on former Post Office head
The story behind victims of faulty Horizon accounting software

Here's an overview of how the process works and who is involved:

• Someone contacts the Cabinet Office naming the individual in question and explaining the reasons why they believe their honour should be revoked
• The committee meet and consider the case
• If they decide the honour should be removed, they submit their recommendations for forfeiture through the prime minister to the King
• The King approves the decision and a notice of forfeiture is usually placed in the London Gazette - the UK's official public record.

Is the public told when a case is being considered by the committee?

The committee cannot comment on whether the recipient of an honour is being considered for forfeiture.

The public only ever gets notified once the honour is officially removed.

What happens when the honour is taken away?

The former honour holder is asked to return their insignia (badge or medal) to Buckingham Palace and can no longer make any reference to having an honour in the future, including on websites, publications or business cards.

While the person can technically still be considered for honours in the future, the government says it is "unlikely" that they would "be considered a suitable role model in the future".

It's worth noting that the Forfeiture Committee is not an investigatory body - it does not decide whether someone is guilty or innocent of anything.

Instead, it makes a recommendation on whether the honours system has been brought into disrepute.

The subsequent removal of an honour by the King has no legal implications at all.

Can honour holders appeal the decision?

Recipients may be asked to give written representations during the decision process if the Forfeiture Committee feels that evidence against them is not clear-cut, but the government gives no guidance on whether recipients can appeal once the honour has been removed.

It does say that honours can be restored once they have been removed, referring mainly to scenarios where convictions have been quashed for the offences that led to the initial decision.

Can an honour be forfeited voluntarily?

Yes. While an honour can only be formally forfeited by the King, a recipient can renounce their honour voluntarily - in other words, stop referring to themselves as a CBE - and then go through the official processes of having it officially annulled.

They would still hold the honour until the King annulled it.

Are honour removals common?

It happens quite a lot; the last list of forfeitures published for 2023 had a dozen removals, mainly for criminal convictions.

Here is a list of some high-profile individuals who have been stripped of their honours. These were due to crimes.