Not really - Labour policy is to keep every option on the table. Only by those options being reduced down - by the PM ignoring them (like the cross party talks), by being defeated in the house (as on the no confidence vote) - do you get to the point at which a second referendum is viable.
Even then, you have to ensure it passes and that the Government cannot set the terms of it (ie: that they can't offer no deal vs May's deal vs remain, or that they allow the same funding issues that Leave benefited from last time).