May has repeatedly rejected the idea of a second referendum on leaving the bloc, but the campaign for a so-called “People’s Vote” has attracted some support in Parliament.
If the prime minister’s deal is voted down on Tuesday — as many analysts expect will happen — the government would then have 21 days to file a parliamentary motion detailing how they plan to proceed.
The People’s Vote campaign said in the report that lawmakers should amend the motion by calling for a second referendum.
The U.K. would then be forced to extend its timetable for leaving the EU to allow enough time for another referendum, which is likely to take months to organize.
Holding a second referendum on Brexit would almost certainly require an extension of Article 50 to push back the March 29 deadline. But, that is no simple task — all EU countries would need to agree to a deadline extension at a vote of the EU Council.
Nonetheless, the People’s Vote argues all other EU member states would “willingly agree” to extend Article 50.
“It is our view that in these circumstances the EU would grant an extension, and that the government would not face any political or procedural obstacle to holding the People’s Vote that could not be overcome,” the report said.