Wednesday’s Cabinet meeting is due to take place at the Prime Minister’s country retreat Chequers and working on the UK’s divorce from Brussels will be at the top of the agenda.
Mrs May has tasked her colleagues with setting out the opportunities that leaving the European Union (EU) will create in each of their portfolios.
The Cabinet will meet to discuss Brexit as it appears increasingly likely that Mrs May will not seek Parliament’s approval before formally triggering Article 50, which will kick off a two-year period of exit negotiations between the UK and the EU.
Downing Street has said MPs will be given “a say” on the process for the UK’s departure from the EU.
However, a spokesman declined several opportunities to say whether Parliament will be given a formal vote on the triggering of Article 50 when pressed by reporters on Tuesday.
Number 10 has insisted there is “no legal obligation” for Mrs May to consult Parliament before invoking the Article.
The comments leave open the possibility that negotiations could be launched without the approval of MPs being sought and Parliament could debate the issue without a formal vote taking place.
Downing Street has also confirmed that Mrs May will not hold a second referendum or an early general election to give voters the chance to sign off on any deal struck between the UK and the EU.
Mrs May is also expected to use the Cabinet meeting to compare Tory party unity with the turmoil within the Labour Party, despite reports of an ongoing feud between the ministers in charge of the main Brexit departments: Boris Johnson, Liam Fox and David Davis.
The UK’s future outside the EU will be a key issue during the Prime Minister’s first full week back at work following her summer holiday in Switzerland as she travels to the G20 summit in China at the weekend.
The summit will represent Mrs May’s first international trip outside Europe as Prime Minister and she is expected to use it to highlight post-Brexit opportunities to other world leaders.
The Cabinet meeting at Chequers has prompted the SNP to accuse the Government of showing “breathtaking complacency”.
The party’s European affairs spokesman Stephen Gethins said: “It is over two months since the result of the Brexit referendum and ministers are only now being asked to come up with their ideas about how it might work at a ‘country house away day’.
“This is breathtaking complacency from a government that got us all into this mess in the first place.”
Anna Soubry, a former business minister and a prominent campaigner to stay in in the EU, told the BBC Radio 4 Today programme: “It is for the Brexiteers - the British people now have voted for us to leave the European Union, these are the people who now have to deliver on it.
“So the three Brexiteers - David Davis, Liam Fox, Boris Johnson - they are the ones who have to show us what progress they have made, what Brexit is beginning to look like, what successes or failures or difficulties they have had.
“It is for the Brexiteers now to deliver for the British people because they have spoken, we are going to leave the European Union, we now need to know what that looks like.”
Ms Soubry also called for Britain to keep its access to the single market and the free movement of people.
She said: “For me, the priorities are first of all access to the single market. It is absolutely critical for British business, and that means for the benefit of people across the United Kingdom, that our country still has access to that single market.
“Particularly important, obviously, for the financial services industry and I’m particularly concerned for our automotive industry which has flourished in our country - we should be hugely proud of it - and they want certainty on tariffs.
“Access to the single market, free of tariffs, free of custom duties. The ability to do what we do now very well, which is to trade without barriers - that, I believe, should continue.
“I am concerned though about any plans to curb immigration.”
Ms Soubry added: “I believe in the free movement of labour from the EU. It has benefited our country, especially business.”
But former chancellor Lord Lawson told the programme: “The British people voted clearly to leave the European Union.
“And they voted in part, but an important part, to abandon, to get away from, the doctrine of the free movement of people.”
He said this has to be implemented, and it is not the job of the Brexiteers alone but “the responsibility of the Government” as a whole.
He said Britain should not “waste time trying to negotiate elaborately” a special trade deal with the EU and that Article 50 should be triggered as quickly as possible.
He added: “Afterall, a long period of uncertainty is bad for the economy, bad for British business, and therefore the sooner this is sorted out the better.”