He was quizzed by MPs about the state of the Brexit negotiations and his views on how the Irish government is handling its side of the talks.
The prime minister is expected to put the deal to a vote in the Commons towards the end of February.
Parliament last month rejected May's deal with the European Union, partly because of concerns it would tie Britain to the bloc indefinitely.
Mrs May has also held talks with Labour, the U.K.'s main opposition party, which says it could support a Brexit deal if the government committed to seeking a close relationship with the European Union after Britain leaves.
"It appears that the Prime Minister has just one real tactic: to run down the clock, hoping that members of this House can be blackmailed into supporting a deeply flawed deal", Labour Leader Jeremy Corbyn told MPs. Some lawmakers are accusing PM May of leaving them with a binary choice on the March 29 withdrawal deadline-her deal or no deal. "We now all need to hold our nerve to get the changes this House requires and deliver Brexit on time".
"By getting the changes we need to the backstop; by protecting and enhancing workers' rights and environmental protections; and by enhancing the role of parliament in the next phase of negotiations I believe we can reach a deal that this House can support", May will say.
May sought to buy time, telling lawmakers they would get another chance to alter her course on 27 February if she had not secured changes to the Brexit deal by then.
Robbins confirmed that the original plan was for the backstop to be designed not as a "safety net" for the island of Ireland but as "a bridge" to a long-term trading relationship between the European Union and the UK, ITV new claim. But any such move would cost Mrs May the support of a big chunk of her Conservative Party.
The EU has ruled out reopening the withdrawal agreement but signalled that changes might be possible to the political declaration that sketches out the UK's future relationship.
Theresa May and the European Union are heading for a high-stakes, last-minute gamble that will decide whether the United Kingdom leaves the bloc with or without a deal, people familiar with both sides said.
His comments come after Theresa May set out plans to bypass Commons rules, in order to get a Brexit deal ratified in time.
Mark Francois, vice-chair of the ERG, told the BBC: "We can not vote for this as it is now configured because it rules out no deal and removes our negotiating leverage in Brussels".
Business leaders have argued that a no-deal Brexit would spell disaster for the UK's economy.
On Tuesday representatives from 32 food industry groups said in a letter to Rural Affairs Minister Michael Gove that the industry was facing a crisis and companies were "now totally focused on working to mitigate the catastrophic impact of a no-deal Brexit".
Figures released this week showed the British economy barely expanding at the end of previous year, as business investment, manufacturing output and construction all declined.