In what is turning into one of the strangest days in the short history of Brexit, some interesting conversations are taking place around Westminster.
Cast your mind back to 2017: The Northern Irish Democratic Unionist Party, you'll recall, agreed to support Theresa May's minority government in exchange for an extra £1bn ($1.3bn) dollars for Northern Ireland.
They then didn't support Theresa May when she came back from Brussels late last year with a Brexit deal.
Why? Because of something called the backstop, which sought to avoid the need for either a border between Northern Ireland and the Republic of Ireland or between Northern Ireland and the rest of the UK. The DUP's concern was that the backstop tied Northern Ireland to the EU indefinitely and left it with no say over its future.

Hardline Conservative Brexiteers in London supported the DUP position at the time, saying that they would not sell out the Union. However, these largely English Conservatives had another issue with the backstop, in that it tied the UK so close to Europe that it meant May's deal was Brexit in name only (Brino, as they call it).
Fast forward to last week and Johnson has struck a new deal with the EU. His deal, however, effectively creates a special status for Northern Ireland, meaning that it will in some respects be closer to the UK than mainland Britain. It also creates an effective border between Northern Ireland and the rest of the UK.
As the debate in the chamber draws nearer to its close, DUP MPs have been arguing with Conservative Brexiteers who they believe have thrown them under the bus for supporting Johnson.
When John Redwood, an arch Conservative Brexiteer who voted against May but is backing Johnson, said that he was concerned about Northern Ireland, a DUP MP shouted in response "well what are you going to do about it."
Privately, some DUP MPs have been telling more liberal Conservatives that they were wrong to defy May. In the words of one Conservative MP, referring to a conversation they'd had with a DUP colleague: "He should have voted for May’s deal and not trusted the English nationalists. I warned him and this morning he had the good grace to thank me and agree that he should have listened to me."
Ouch.