The whole thing is no longer in the hands of the government, but those of Corbyn. Although he is working for a vote of no confidence and a general election, if the party thinks that is unlikely he can force one, he is quite likely to go for the second referendum option. With all opposition parties wanting one and enough Tories who have openly said they would support one, then there is little the government can do. It could well come down in the end to May having to decide if she wants a GE or another vote from the public. Seeing as what happened at the last GE she might well think the vote the lesser of two evils.