A new report from The Guardian alleges that aides to Donald Trump hired an Israel-based private intelligence firm to target former Obama advisers who worked on the Iran nuclear accord, as well as journalists believed to be supportive of the deal, in an attempt to discredit the international agreement and make it easier for Trump to withdraw.

“These are extraordinary and appalling allegations,” former British foreign secretary Jack Straw told the paper, accusing Trump and Israeli Prime Minister Benjamin Netanyahu of “desperation” ahead of a looming May 12 deadline for Trump to either maintain or scrap the deal.

According to The Guardian, the firm targeted former Obama national security advisers Ben Rhodes and Colin Kahl, attempting to “get dirt” on them to discredit their involvement in the deal, known as the joint comprehensive plan of action (J.C.P.O.A.). The firm’s investigations reportedly started shortly after Trump’s trip to Tel Aviv, his first diplomatic trip as president. A source familiar with the campaign told The Guardian, “The idea was that people acting for Trump would discredit those who were pivotal in selling the deal, making it easier to pull out of it.”

Although sources have confirmed that contact and an initial plan of attack was provided to private investigators by representatives of Trump, it is not clear how much work was actually undertaken, for how long, or what became of any material unearthed.