“We are concerned that the West will betray us — and its own principles of liberty, democracy and human rights,” said the man, an Iranian academic and a leader of an underground cell. He cannot be identified for fear of retribution.

Speaking to The Times in a European capital, having recently slipped out of Iran, the senior member of the country’s “Green” movement warned that Iran’s apparent nuclear concessions were merely a ruse to ease international pressure while it sought to crush domestic dissent. “How can you rely on any promises and pledges made by a government that not only stole the June election, has not only killed and raped its own citizens, but also has consistently hidden major parts of the nuclear programme?” he asked.