Speaking to GB News, Mr Wilson said the former Conservative leader was to blame for the issues Northern Ireland is now facing with the Windsor Framework.
He said: “She [Theresa May] made an agreement with the EU that there would be no hard border and no checks at all. And no arrangements put in place to monitor trade between Northern Ireland and the Irish Republic.
“Once she had done that and once we were in that box, then it was always going to be be impossible and very difficult for future Prime Ministers to get that changed.”
Mr Wilson claimed that Ms May’s actions had damaged the Union more than the actions of republican paramilitaries during the Troubles.
“And then of course, we’re left with a situation we have now today. Don’t forget, terrorists tried to drag us out and bomb us out of the Union.
And yet, the Union’s been put in far more jeopardy by the actions of a Conservative Prime Minister, as opposed to the acts of the terrorists who bombed us for 35 years,” he said.
He also criticised former Prime Minster Boris Johnson’s handling of the NI Protocol, along with Rishi Sunak’s Windsor Framework.
“I still believe that Boris Johnson should have stood by his promise or if he had been given agreement that this would be a temporary arrangement, then as soon as he had got the trade agreement with the EU, he should have pushed to have that temporary arrangement replaced with something which was workable, and which kept the integrity of the United Kingdom.”
“So Theresa May put us in the position. Boris Johnson didn’t fight hard enough to get us out of that position. And of course, Rishi Sunak has tried to change it, made some minor changes to it, but the fundamentals are what Theresa May agreed,” he added.
Mr Wilson’s comments come as Jeffrey Donaldson allegedly told the European Research Group (ERG) his party will not rejoin power-sharing at Stormont.
Sir Jeffrey Donaldson reportedly made the remarks to members of the Eurosceptic group which has criticised the Stormont brake after legal experts advised them it was “practically useless”.
He took to social media to clarify his position on Wednesday afternoon ahead of a key vote in Westminster.
“I have consistently indicated that fundamental problems remain notwithstanding progress made,” Sir Jeffrey tweeted.
“Consequently there is not a sustainable basis at this stage to enable us to restore Stormont.
“We will vote against the proposal today and continue to engage with the Government to secure clarification, reworking and change.”