Israel’s military intelligence chief, Major General Amos Yadlin, has confirmed that Iran owned up to its secret nuclear facility in Qom only because it discovered that Western intelligence services were already aware of its existence.

According to other intelligence sources, several months ago, Iran captured a spy operated by MI6 and discovered that Western intelligence services knew about Qom.

The Iranians suspected that the United States was planning to publicise the information during the United Nations General Assembly to embarrass Iranian President Mahmoud Ahmadinejad and push for sanctions against Iran.

To preempt this, the Iranians themselves revealed to the international media the existence of the Qom facility and agreed to subject it to inspections by the International Atomic Energy Agency (IAEA).

General Yadlin confirmed some of these details in a lecture on Monday at the Institute for National Security Studies in Tel Aviv.

He said that Iran is trying to reach the “threshold” from which it can decide, at a time of its choosing, to quickly assemble a nuclear weapon. To do this, said General Yadlin, “the Iranians could use a secret process, as they planned to do with the plant at Qom. This should serve as a warning.”

General Yadlin, in what has become his unofficial annual public report, shared with the audience a limited version of the Israeli intelligence’s estimate of Iran’s current nuclear status.

“Iran’s technological clock has almost finished turning,” he said. “In 2008 they mastered the technology of uranium enrichment and in 2009 they accumulated enough uranium for a first bomb, though it is not enriched so far to a military-grade quality of 93 per cent. “So far they have 1,700 kilos of low-grade enriched uranium and every day, the 4,000 centrifuges in Natanz produce a few more kilos.” General Yadlin said that the Iranians are also “advancing on a broad front in their research efforts”. They are improving the range and accuracy of their solid-fuel missiles and working on a nuclear-triggering device, “which disproves their claim that the nuclear programme is for peaceful means”.

Iran’s main objective, he said, is to achieve the status of a “threshold state. Once they are there, they won’t have to actually assemble a nuclear device to enjoy the advantages. Iran’s allies will automatically begin to allow themselves moves they previously would never have dared to take. And the Arab states, in the Gulf and Egypt and Jordan, will also feel that they have to pursue their own nuclear programmes.”