Prime Ministers Scott Morrison and Boris Johnson will reveal the in-principle agreement on Tuesday morning London time, although the leaders are already celebrating the deal.
"Their agreement is a win for jobs, businesses, free trade and highlights what two liberal democracies can achieve while working together," a spokesman for the prime minister told AAP.
If the agreement is set, it will mark the first negotiated from scratch since the UK exited the European Union.
Here’s what we know:
Workers and backpackers
The deal is expected to make it easier for Australians to live and work in the UK.
The Australian Government is also planning to scrap the farm work requirement for British backpackers.
As it stands, UK backpackers on working holiday visas are required to complete 88 days of farm work.
However, that looks set to be scrapped.
“If a Brit comes to Australia, if they want an extension of their visa, we have said to them that they have to do 88 days on a property in regional Australia to get an extension for the second year,” Littleproud said.
“(Britain) is saying ‘We want to equalise that’.”
However, The Nationals have expressed concerns that the deal will exacerbate the shortage of farm labour in Australia by another 10,000 workers.
“As the United Kingdom moves into a completely new generation of their trading relationships with the world, who better to start that journey with than Australia?" Morrison said.
"The Brexit that has occurred is an opportunity for us to pick up where we left off all those many years ago and to once again realise the scale of the trading relationship we once had."
However, one of the major sticking points of the free trade agreement has been Australian access to the UK market.
UK beef farmers have been concerned they will be undercut by cheaper Australian products, however Australia wants to be able to sell products in the UK essentially without tariffs.
As it stands, trade in goods and services between the UK and Australia is worth AU$25.7 billion, with wines, cars, metals and medicines forming the core of the trade relationship.
A spokesperson for the UK Department for International Trade in May said any deal “will include protections for the agriculture industry and will not undercut UK farmers or compromise our high standards”.
Union concerns: Multinationals and medicines
The Australian Council of Trade Unions (ACTU) and UK Trade Unions Congress have both called for greater protections for workers in the trade agreement.
“The Australian and UK Governments have rushed to conclude negotiations on this deal, without any public consultation or scrutiny,” ACTU president Michele O’Neill said.
“We call on the governments to be transparent about the contents of this ‘in principle’ agreement, and immediately begin consultations with trade unions about the detail of the agreement.”
She said the decision to include Investor-State Dispute Settlement (ISDS) was especially concerning as it provides multinational corporations with the right to sue governments over actions that could compromise profits.
“Australia knows all too well the dangers of ISDS, having been sued by Philip Morris tobacco company for billions over our plain packaging laws - a case that took years and which Australia eventually won, but still ended up having to pay $12 million in legal fees,” she said.
The ACTU also expressed concerns the deal will mean it takes longer for Australia to access cheaper, generic medicines.
“The Australian Government have caved in to the UK’s demands on patents for pharmaceuticals, which could mean Australians have to wait an additional 3 to 5 years for cheaper versions of medicines to be available,” O’Neill said.
“This could cost the PBS hundreds of millions of dollars per year.”
Morrison and Johnson will announce more details of the in-principle agreement at 9am DST (6pm AEST).