A winning strategy: UN Security Council and no sanctions
Iran cannot be taken to the Security Council because of a delay in reporting some legal facilities, or based on an unproved suspicion (some members may have). EU3 and USA tried their best to criticize Iran and ratified an IAEA resolution to make Iran re-suspend its Isfahan facility. But Iran rejected the resolution calling it self-contradictory and illegal. IAEA resolutions are not legally binding and there is no problem with rejecting it.
However, EU3 are now playing another strategy. They need allies to send Iran's case to the Security Council; and in order to do so they need to play smooth. The members who object the referral of the case to the Security Council are afraid of sanctions that may increase oil prices to 100$ a barrel. EU is actively arguing that it will not seek immediate sanctions against Iran. This is their winning strategy for which other members will not object the referral.
What's next? Any resolution ratified in UN Security Council is LEGALLY BINDING. This can make Iran scrap its nuclear programs. End of the story.