The six MPs were taken aback by the hardline approach of the Pentagon and in particular Ms Cagan, one of Mr Bush's foreign policy advisers.Another UK report: American diplomats have been ordered to compile reports detailing any possible Iranian actions or violations of international law that some fear could be used to justify military strikes.
She made it clear that although the US had no plans to attack Iran, it did not rule out doing so if the Iranians ignored warnings not to develop a nuclear bomb.
It was her tone when they met her on September 11 that shocked them most.
The MPs say that at one point she said: "In any case, I hate all Iranians."
Although it was an aside, it was not out of keeping with her general demeanour.
"She seemed more keen on saying she didn't like Iranians than that the US had no plans to attack Iran," said one MP. "She did say there were no plans for an attack but the tone did not fit the words."
Another MP said: "I formed the impression that some in America are looking for an excuse to attack Iran. It was very alarming."
Ms Cagan, whose job involves keeping the coalition in Iraq together, also criticised Britain for pulling out troops.
"She said if we leave the south of Iraq, the Iranians will take it over," said one MP.
Another said: "She is very forceful and some of my colleagues were intimidated by her muscular style."
ADDED - War with Iran - we can't afford it.