It's not that Labour wants to hold another referendum that's the issue.
The issue is their overall plan: dismiss this deal as Tory nonesense, negotiate a new and much better deal and offer that or Bremain, while staying neutral in the campaign.
That is the second worst approach imaginable (the worst being what's going on right now). First of all, it assumes you can negotiate a new and much better deal at all. There is no reason to expect EU will be in the mood for much more negotiating. Second, there's no reason to assume you can negotiate a much better deal. Staying netural in the campaign is abdicating their responsibility as political representatives of the nation. Finally, there is no "no-deal Brexit" option, which means the referendum result will be painted as illegitemate by the opponents.
Labour plan has the seed of a solution, nothing more.
Here's what needs to be done: There needs to be a time-limited debate on what is expected from a new deal. The time limit must be short enough to keep interest (7-30 days), the debate public and the wish must be realistic. If no realistic proposal for a deal can be made this should be communicated to the public, this is about the only thing that can happen. Then the referendum must be called, between either Bremain and no-deal Brexit, or else a threeway between Bremain, whatever deal is realistic (current deal +-) and no-deal Brexit.
The threeway referendum should either be in the form of a transferable vote or else two referendums with two ballots. The first ballot is whether the deal should be ratified or not, the second ballot is only counted if no wins and asks the question between no deal Brexit and Bremain. If Bremain wins the law should stipulate the question of Brexit is not debated again by Parliament for at least 10 years, to allow time to heal.
That's how you unboil this particular egg. Whatever wins, wins. Even if there's a no-deal Brexit, at least it has a democratic mandate behind it, not this weird septic tank of an issue.
McHrozni