The topic of a second referendum on Brexit has been discussed since the time of the first referendum. However, recently, there is a lot of talk in UK politics about a "confirmatory" referendum.
For example, the BBC news on 4 April 2019:
"Labour ordered its MPs to vote in favour of a "confirmatory referendum" on a Brexit deal, but [UK Labour party chairman] Mr Lavery abstained."
Or Chuka Umunna, of the newly-formed Independent Group of MPs, quoted in the Observer, 6 April 2019:
"...our support for a confirmatory People’s Vote is 100%."
My question is, is a "confirmatory" public vote just another word for a second referendum, or does the word "confirmatory" have a specific meaning, for example, in regards to what options would be on the ballot paper? In other words, would a confirmatory vote be different from a second referendum, or are they just different words for the same thing?
Thanks to the useful hint from origimbo here, I was able to find the text of the two amendments that were voted on regarding the "confirmatory" vote. For reference, they are "Margaret Beckett's motion M (Confirmatory public vote)," defeated on 27 Mar by 295 votes to 268, and "Peter Kyle's motion E (Confirmatory public vote)," defeated on 1 Apr 2019 by 292 votes to 280. They both have identical text, which is as follows:
That this House will not allow in this Parliament the implementation and ratification of any withdrawal agreement and any framework for the future relationship unless and until they have been approved by the people of the United Kingdom in a confirmatory public vote.
This doesn't help much though, because it doesn't say explicitly what makes the vote a 'confirmatory' one.
Why this matters
The 'Confirmatory public vote' proposal (quoted above) has a couple of features that might differentiate it from any other referendum that might be held on Brexit. Firstly, it restricts what parliament can do (it can't implement and ratify a withdrawal agreement without the approval of the public, or at least, that's what it seems to say), but secondly, it doesn't specify what happens if the public doesn't approve the agreement. If the public votes no in such a referendum, it doesn't specify whether would that result in remaining in the EU, or whether would it result in leaving with no deal.
I suspect this ambiguity is deliberate, since it allows the idea to appeal to both hard brexiters (for whom a no deal exit might be the preferable option), as well as remainers (for whom staying in the EU would be the preferable option).
However, because of this, when someone says they support a "confirmatory vote", I am not sure if they mean "I support a referendum whose outcome is binding" or "I support a public vote, but not necessarily one in which remain is on the ballot." These are not mutually exclusive of course, but they are very different things. This why I'm after concrete information backed up with sources about what the word "confirmatory" is understood to mean, among the MPs in the British parliament who are making such statements.