We promised to explain what a censure motion is - speaker Lindsay Hoyle will shortly let us know whether he is going to allow one - so here goes.

A censure motion is a symbolic motion which allows MPs to criticise government policy, an individual minister or the government as a whole.

Any MP can table one, and it only takes a simple majority to pass.

However, the Conservatives have a working majority of 75, so many Tory MPs would have to side with the opposition in order for it to pass.

According to the Institute for Government, external, if a censure motion passes, it's essentially a political move.

In this case, it wouldn't force Johnson to do anything, but would put him under far greater political pressure.

Allegations of parties in Whitehall first surfaced late last year. Let's recap how Johnson has reacted since then - it matters because opposition parties say he has misled Parliament.

1 December 2021: Asked if there was a party in Downing Street on 18 December 2020, Johnson said "all guidance was followed completely in No 10".

8 December: After the leak of a video showing No 10 staff joking about the 18 December event, he said had been "repeatedly assured" that "there was no party and that no Covid rules were broken".

Later that day he told the Commons he was "sure that whatever happened, the guidance was followed and the rules were followed at all times."

12 January: He apologised for attending a Downing Street garden party on 20 May 2020 but said he had "believed implicitly" it was a work event.

The event:

• Boris Johnson, his wife, and Chancellor Rishi Sunak both paid fines for attending a surprise birthday celebration for the PM in the Cabinet Room on 19 June 2020.

• Up to 30 people attended, sang Happy Birthday, and there was a cake. At the time, gatherings of more than two people inside were banned by law.

The apology:

• The PM said he "fell short" of observing his own rules but rejected calls to resign, saying he feels a duty to "get on with the job" and "deliver on the priorities of the British people".

At around 16:30 BST the prime minister will face MPs for the first time since he was fined for breaking his own Covid rules.

Technically, he’s updating MPs after the Easter break - and therefore may wish to focus on other matters such as Ukraine - but plenty of drama is still expected.

(As you may remember he was fined last week, but Parliament was on its Easter break and he resisted calls to bring MPs back early.)

But before that, at 14:30 BST, we'll hear whether the Speaker will allow a censure motion to go ahead. (More on what a censure motion is later, along with detail about when this will be, if it happens.)

In short, it's effectively a slap on the wrist, but opposition parties are hoping this will be allowed as it'll be one way to formally hold the PM to account.

Later this evening, Boris Johnson will address Conservative MPs.

Unlike his Commons statement, this will happen behind closed doors - but there’ll be plenty of journalists with their ears to the door and many MPs who will want to offer their verdict on the PM’s performance.

Welcome to today’s live political coverage; MPs are descending on Westminster for Boris Johnson’s first Commons statement since he was fined for breaking his own lockdown rules.

It’ll be a long day for Johnson, who will first address MPs in the Commons, and later face his own Tory MPs behind closed doors.

The prime minister has vowed to “set the record straight” in his update following the Easter recess at around 16:30 BST.

First, we'll hear from Home Secretary Priti Patel about the plans to send some migrants arriving in the UK to Rwanda - that will be at 15:30 BST.

We’ll bring you every twist and turn here on the live page.