?Theresa May's minority government allies the DUP would not repay the £1 billion funding deal given to Northern Ireland under a "confidence and supply" arrangement if their pact ended, Sammy Wilson has said.
Sammy Wilson claimed the agreement between his party and the Conservatives would be "finished" if the British prime minister's Brexit plan successfully cleared the Commons, but vowed to continue to support the government if it was voted down.
In an interview with the Press Association, Mr Wilson said the "threat" to Northern Ireland would be removed if the deal was defeated, in which case the DUP would be "committed to supporting the government throughout the life of this Parliament".
And he dismissed suggestions his party would consider abandoning the government if there was a confidence vote, saying that there would be "no reason" to support it if Mrs May's deal failed to get through the Commons.
Mr Wilson said: "Ironically, voting down a deal is probably more likely to ensure the confidence and supply arrangement goes on...
Quiz: Who said it - Sammy Wilson or Donald Trump?
"It may well be that this could go through. If it goes through and she persists with this deal then the confidence and supply arrangement is finished, because we couldn't possibly support a government that was persisting in breaking up the Union.
"But our focus at the minute is on making sure that the deal doesn't go through, and if the deal doesn't go through, then the arrangements we would have with the Conservatives - well, why would we break it?"
Asked whether the DUP would pay back the £1 billion given to Northern Ireland if the agreement ends, Mr Wilson said: "No, I don't think so, because don't forget we've already delivered over nearly a two-year period now on what the government needed.
"If you look at our voting record, 50% of the votes that were required to get the Withdrawal Bill through relied on our support.
"Twenty per cent of domestic legislation wouldn't have got through had it not been for our support - so we've already actually delivered for the government on this and it was only a two-year deal we had with them as well."
Under the terms of the deal, agreed after Mrs May lost her Commons majority in last year's general election, the Northern Ireland party is supposed to back the government on Budget matters and on confidence votes.
But the East Antrim MP accused the government of being at fault if the agreement were to break, and said the DUP's stance was "absolutely" worth the potential fallout.
"The deal that she's got at present are on terms of such enormity that either the UK as a whole has to stay in the EU in the worst possible terms or else the UK has to accept to free themselves from those terms, they've got to allow the break-up of the union," he explained.
"Now neither of those two choices to me are choices which any government should contemplate taking."
He also criticised Mrs May - claiming she is "a woman who doesn't listen" - but refused to be drawn on who he would rather lead the Tories.
"She wouldn't be in this pickle if she'd listened to us, because we warned her ... that if she persisted down this road of the backstop that, one, she was going to lose our support and, secondly, she'd be held to ransom by the EU."
He added: "It was never in our interest to sour relationships with the government, but that souring of relationships has been brought about by the way in which she has behaved."
Sinn Féin's deputy leader Michelle O'Neill accused the DUP of engaging in a "circus" while ignoring the "clear will of citizens and industry" in Northern Ireland.
She said: "The latest wranglings in Westminster are little more than theatre which is motivated by the civil war in the Tory Party rather than the substantive issues.
"The DUP is playing a full role in this circus while ignoring the clear will of citizens and industry here who are opposed to Brexit and opposed to any attempt to renegotiate or dilute the backstop as contained in the Withdrawal Agreement."
