The DUP's Sammy Wilson has said his party is not backing a second Brexit referendum.
The DUP supported the Letwin amendment, two days after they rejected Boris Johnson's new Brexit deal.
Mr Wilson said his party's votes "were significant" in the passing of the amendment.
"It is far from the first time that DUP votes have been crucial on the issue of Brexit," he added.
"In nearly half of all votes on the issue in Parliament, it has been DUP MPs who have ensured progress continued to be made towards our exit from the EU.
"The DUP wants to get Brexit done but it must be a Brexit for the whole of the United Kingdom. Our position has been clear and it has been consistent.
"DUP MPs supported the Letwin amendment as the only avenue available to properly scrutinise the deal on offer and attempt to secure changes that could address some of the concerns we have.
"It was a situation that could have been easily avoided had the Prime Minister kept to words he penned to Jean-Claude Juncker just a matter of two weeks ago."
The DUP's Brexit spokesman moved to quash any suggestions the DUP would support a second referendum.
"The DUP does not seek a second referendum, merely implementation of the first," he said.
His comments came hours after the Prime Minister got a senior diplomat to send an unsigned photocopy of a letter asking for an extension.
"The people of the United Kingdom were asked whether the UK should leave the EU, not whether Great Britain should leave Northern Ireland behind," Mr Wilson added.
"We want to leave as one nation. That remains our goal.
"If the Prime Minister remains willing to achieve that outcome he will find DUP MPs as willing partners in that project."