Both houses backed the "Brexit bill" and after securing symbolic approval from Queen Elizabeth, expected in the coming days, May has the right to begin what could be Britain's most complex negotiations since World War ll.
Once Theresa May triggers Article 50, the United Kingdom will have two years to negotiate a deal with Europe, including trade, free movement of persons and countless other issues.
"The simple truth is we have been planning for the contingency - all the various outcomes, all the possible outcomes of the negotiations", Davis said.
Ms May also warned the SNP it was "not a moment to play politics or create uncertainty" after Nicola Sturgeon launched plans for a fresh referendum on Scottish independence before Britain leaves the EU.
The EU may be seen to have the upper hand in the negotiations.
"We remain on track with the timetable I set out six months ago", Mrs May told parliament last night, referring to her promise to trigger Article 50 by the end of March.
United Nations urges action to avert world's 'largest humanitarian crisis'
The humanitarian chief said in Somalia the current indicators mirrored the tragic picture of 2011 in the country when some 260,000 people died of starvation .
On Sunday, Brexit secretary David Davis urged MPs to overturn the amendments on Monday and sought to reassure Conservative rebels and others by saying that the issue of European Union citizens' future after Bexit will be "the first thing" on the agenda when talks begin.
British citizens should be able to choose to keep various benefits of EU membership including the freedom of movement after Brexit, the European Parliament's chief negotiator has said.
Mrs May has revealed little of her strategy in the Brexit negotiations but has a long wish list - wanting to win a free-trade deal, maintain security cooperation, regain control over immigration and restore sovereignty over British laws.
For Labour, shadow Brexit secretary Keir Starmer argued there was a "compelling case" to give European Union residents the certainty they deserved, arguing that "not only is it the right thing do in principle but it would set the right tone ahead of the negotiations".
It is expected in late May to early June - almost a year after Britain's referendum vote to leave the bloc.
In a letter to The Times, which is signed by Louise Richardson, the Oxford vice-chancellor, and the heads of all but three of the colleges, the academics dismiss as insufficient the indications by ministers that European citizens already resident in Britain were likely to be allowed to stay. "I don't think the consequences of no deal are by any means as apocalyptic as some people like to pretend", he said.
"Making an equivalent mistake would constitute a serious dereliction of duty by the present administration", they said in the report.