May faces legal challenges over whether she can begin the process without MPs' approval, but she has reportedly been informed by UK government lawyers that no approval is necessary.
The legal advisors are said to have told her that Westminster's consent is not required to trigger article 50 and that the Prime Minister "may consider asserting Royal Prerogative."
The development emerged as May is set to chair a meeting of senior ministers to discuss how Brexit could be a success in their particular areas.
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The meeting will take place on Wednesday, after reports of a government split over whether or not the UK should try to retain its membership of the single market.
Ahead of the meeting, Britain's opposition Labour Party has condemned any attempt to trigger article 50 without Parliament.
Barry Gardiner, Labour's shadow secretary of state for international trade, Europe, energy and climate change, said: "Those commentators who argue that the Prime Minister should circumvent a parliamentary vote and use the Royal Prerogative to leave the EU should consider what constitutional precedent they seek to invoke.
"The logic of saying the Prime Minister can trigger article 50 without first setting out to Parliament the terms and basis upon which her government seeks to negotiate; indeed without even indicating the red lines she will seek to protect, would be to diminish parliament and assume the arrogant powers of a Tudor monarch.
"Parliament cannot be side-lined from the greatest constitutional change our country has debated in 40 years."
His comments are in stark contrast to former Tory leader Iain Duncan Smith, who supported the Leave camp and has claimed that cabinet members, including May, want to start the formal process of leaving the EU early in 2017.
The former UK work and pensions secretary said article 50 should be triggered in the first quarter of the new year to "provide focus" and a two-year deadline for Brexit negotiations.
Smith claimed key figures in the cabinet supported an early exit from the EU.
"I have spoken to them and I am certain that these characters - David Davis, Liam Fox and Boris Johnson, and the Prime Minister by the way - are very clear that they need to get on with triggering article 50 as soon as possible early in the new year," he said.
Meanwhile, it was also reported on Monday that UK finance minister Philip Hammond wants to see Britain retain access to the single market in specific sectors such as financial services, while also securing border controls for the UK.
Hammond wants to ensure that the upcoming negotiations on Britain leaving the EU protect particular parts of the economy before a meeting of the cabinet on Wednesday at Chequers.
According to UK press reports, a number of senior figures, including Hammond, believe that all options, including staying in the single market, should remain on the table even if it means fewer restrictions over immigration.
This is believed to be in contrast to other ministers, including Davis and Fox, both of whom backed the Leave campaign, who are thought to be more hawkish about Britain's exit plans.
Elsewhere, the former head of Britain's civil service believes Brexit is not inevitable and Britain could still remain a part of a reformed EU.
Gus O'Donnell said the UK could stay in a more "loosely aligned" EU, arguing it could take "years and years and years" to separate fully and that the whole project could change in that time.
He said, "Lots of people will say, 'We've had the referendum, we've decided to go out, so that's it, it's all over'. But it very much depends what happens to public opinion and whether the EU changes before then."
Even so, he still feels it unlikely that any reform would be radical enough and the chances of remaining a part of the EU were very low.
O'Donnell also urged caution in triggering article 50 without a strategic plan in place, arguing that the exit mechanism from the EU was designed to favour the countries that were staying in the Union.
EU leaders, with the notable absence of May, will meet at an informal summit on 16 September in Bratislava to discuss the future of the EU. The Brexit negotiations are expected to dominate the gathering in Slovakia.
The day before, European Commission President Jean-Claude Juncker is due to deliver the annual state of the union address in the European Parliament in Strasbourg.