Sue Gray: When will the Downing Street parties report be published?

Boris Johnson has promised to fight on as prime minister after facing more calls to quit over lockdown parties in Downing Street.

MPs are still waiting to see the findings of an investigation into the events by an important woman called Sue Gray, which had been expected on Wednesday.

The BBC understands that Ms Gray's report is essentially completed, but she has not yet sent it to the prime minister.

But who is Sue Gray and what is her report looking into? Keep reading to find out.

Who is Sue Gray?

Sue Gray is leading the investigation

Ms Gray is currently second permanent secretary at the Cabinet Office - a senior civil servant.

A civil servant is someone who helps the government carry out its work but they are not elected politicians.

She may have spent most of her career in the civil service, but in the late 1980s she did take a career break to run a Northern Ireland pub called the Cove Bar.

Her husband is a country and western singer called Bill Conlon.

What is Sue Gray investigating?

Seventeen gatherings allegedly took place in either Downing Street - where the prime minister lives and works - or other government departments during the coronavirus pandemic, according to media reports.

Most recently Downing Street has admitted staff gathered with Boris Johnson inside Number 10 to wish him a happy birthday on 19 June 2020, during the first Covid lockdown.

Rules at the time banned most indoor gatherings involving more than two people.

Ms Gray has been asked to look at the nature and reasons for the gatherings, including who went to them, taking into account the coronavirus restrictions at the time.

Boris Johnson has been under a lot of pressure after the claims of illegal gatherings in his home and place of work - 10 Downing Street

The investigation team has been able to speak to current and former members of staff. For example, the BBC has been told the PM's former adviser Dominic Cummings was approached by Ms Gray's team.

She has no power to give out punishments to anyone if the report reveals that any rules were broken.

But what she says will be important for the future of the Prime Minister.

It seems likely Mr Johnson and other Members of Parliament may have to wait until Thursday - or beyond - to see the report.

What is the Metropolitan Police investigation?

Met Police Commissioner Cressida Dick - pictured here with Boris Johnson in 2019 - confirmed the force would look into "potential breaches of Covid-19 regulations".

This is a different investigation from Sue Gray's.

Police say they are looking at "potential breaches of Covid-19 regulations" in Downing Street and other government departments since 2020.

But the decision to start the investigation was the result of information provided by Ms Gray's team, Metropolitan Police Commissioner Cressida Dick said.

The Met's announcement means parts of the Sue Gray report will not be published until after the police investigation is completed, the prime minister's spokesman said.