Aides to Donald Trump, the US president, hired an Israeli private intelligence agency to orchestrate a “dirty ops” campaign against key individuals from the Obama administration who helped negotiate the Iran nuclear deal, the Observer can reveal.

People in the Trump camp contacted private investigators in May last year to “get dirt” on Ben Rhodes, who had been one of Barack Obama’s top national security advisers, and Colin Kahl, deputy assistant to Obama, as part of an elaborate attempt to discredit the deal…

One former high-ranking British diplomat with wide experience of negotiating international peace agreements, requesting anonymity, said: “It’s bloody outrageous to do this. The whole point of negotiations is to not play dirty tricks like this.”