The husband of jailed British mother Nazanin Zaghari-Ratcliffe said he is disappointed in the failure of Boris Johnson's efforts two years on from her arrest in Iran.
Richard Ratcliffe said the battle to set his wife free has become a "test of endurance", particularly after the Foreign Secretary's unsuccessful bids to secure her release.
Ms Zaghari-Ratcliffe, a British-Iranian dual citizen serving a five-year prison sentence after being convicted of spying charges, was arrested at Tehran Airport on April 3, 2016.
She denies the charges and maintains she was in Iran to introduce her young daughter Gabriella to her parents.
Ahead of the second anniversary of her detention, Mr Ratcliffe said: "We didn't expect to be needing to mark this anniversary - not after the hopes of Christmas and the Foreign Secretary's word.
"But it remains a cold late Spring. Nazanin was told that if she wasn't home by Christmas, at least it should be done by Nowruz, and we should worry if we go past March 2018, with the storms that might lie ahead. And now we have."
He added: "Our story has become a test of endurance, and there is a need to recharge spirits - particularly after the disappointment of the Foreign Secretary's mission failing to deliver, and Nazanin becoming caught up in this government stand off - so we wanted the anniversary to be an occasion where we drew positive energy.
"That is what the outside can do, and we are grateful for people's care."
Tulip Siddiq, Ms Zaghari-Ratcliffe's MP, said: "In November the Foreign Secretary promised to 'leave no stone unturned'. But since his trip to Tehran, he has been missing in action.
"Nazanin does not have the luxury of time, and Boris Johnson must act before her situation gets worse.
"If he can't deliver on this, then it is time that the Prime Minister stepped in."
Mr Ratcliffe said recent weeks have been a low point for his wife in Iran, and she has suffered periodic panic attacks in her sleep.
The key question is whether Mr Johnson has "given up on his promise to bring home Nazanin soon", the Free Nazanin campaign said.
Mr Ratcliffe and his supporters have requested to meet Mr Johnson with lawyers present, to ask what are Nazanin's rights in his view as the stand off continues.
The campaign for Nazanin's freedom said they have previously discussed with the Foreign Secretary's office that it is a contortion to claim that her case is just a normal consular case.
"Given that Nazanin is held for something the government has not done, not because of something she has, the claim she is just another consular case belittles the government's obligations," the campaign said.
On Monday, the Free Nazanin campaign will hold a #ChooseLaughter event in Fortune Green in West Hampstead, north west London, where they will hang jokes and "things that make us smile" provided by supporters and prisoners.
A Foreign Office spokeswoman said: "On the second anniversary of Nazanin's arrest we continue to approach her case, and all of our British-Iranian consular cases, in a way that we judge is most likely to secure the outcome we all want.
"Therefore we will not be providing a running commentary on every twist and turn."