The findings of the Integrated Review are set to be announced by the Prime Minister today.
The major review will consist of 100 pages, and will outline Boris Johnson's hopes for the UK in 2030, and how they will be acheived.
It will examine defence, security and foreign policy, and has previously been dubbed the biggest review of its kind "since the end of the Cold War".
James Cleverly, Minister for the Middle East and North Africa, told the Commons last month that the Integrated Review "will send a message about what the UK stands for as an independent actor on the global stage".
The review, which had been expected to be revealed by mid-February, looked to be delayed again at the start of this year, after Boris Johnson said that timeframe was "a little bit premature".
The aim of the review is to cover "all aspects of international policy from defence to diplomacy and development", with the Prime Minister describing it as the "biggest review of our foreign, defence, security and development policy since the end of the Cold War".
Its first phase took place with the announcement of £16.5bn extra funding for the Ministry of Defence (MOD).
What is the Integrated Review?
The Integrated Review was launched in February 2020.
Boris Johnson told Parliament that "by transforming this country's economy and by raising productivity, we will ensure that defence and security are amply provided for".
Downing Street had previously said the Integrated Review will go beyond the parameters of a traditional strategic defence and security review (SDSR) by looking at the "totality of opportunities and challenges" the UK faces.
The aim is for British military chiefs to use the review to reshape the Armed Forces, with decisions made according to threats facing the country, with it also looking at developing defence capabilities and procurement.
Defence, foreign and security policy, threats of the next decade, relationships with allies and changing strategy on the international stage will also all be examined.
Watch: What questions the Integrated Review will answer for defence.
After being temporarily paused in April due to the coronavirus pandemic, the review resumed in June 2020, with the Government inviting submissions of evidence in September.
During a briefing in September, Defence Secretary Ben Wallace warned that the UK's enemies have "studied our vulnerabilities and adapted far more quickly than us", adding that the review will "represent a step-change – not just in how we adapt to the threat, but in how Whitehall faces up to the difficult decisions that must be made".
"In the past, too many reviews were over-ambitious or underfunded or both," he continued.
"Too often the budget, not the threat, did the talking. So we will pivot away from what we have become used to and instead reshape our Armed Forces to become a force fit for tomorrow’s battles, not fighting yesterday's."
In January, Mr Ellwood criticised the news that the publication of the Integrated Review findings had been pushed back again, saying this is now "well overdue".
"I would really encourage this Government to continue and conclude this important exercise," he said.
Mr Ellwood said: "This was the opportunity to regroup, but more than that, it’s also to confirm our ambitions in the world, to check and understand our threats that we face and give clarity as to what our defence posture should be."
The chair of the Defence Select Committee added: "We have a change of the guard in the White House, we have a new determination, a sensible resolve if you like, by President Biden to regroup Western concerns about what’s going on around the world, to stand up to geopolitical threats.
"We want to be part of that and we can only do that if we complete this review."
The current practice of undertaking a strategic defence and security review (SDSR) every five years dates back to 2010.
The most recent SDSR was published a few months after the 2015 election.
Recommendations from the review are expected to be implemented over a period of several years.
For more discussion on the Integrated Review, click through to this week’s episode of the Sitrep Podcast.