The wife of a British academic jailed for life in the United Arab Emirates for allegedly spying says Jeremy Hunt has vowed to do "everything in his power" to secure his release.
Speaking after meeting the foreign secretary in London, Daniela Tejada said Mr Hunt had assured her he was committed to seeing Matthew Hedges freed and returned to the UK.
The 31-year-old PhD student was sentenced to life behind bars at a court in Abu Dhabi on Thursday, six months after he was arrested at Dubai Airport and accused of spying in the UAE.
Ms Tejada told reporters outside the Foreign Office that seeing him "shaken" in court was "beyond heartbreaking", and was pleased the UK government was "now standing up for one of their citizens".
She added: "This is not a fight I can win alone."
Earlier on Thursday, Mr Hunt - who is understood to have met the UAE ambassador in London - said he had seen "absolutely no evidence" to support the charge brought against Mr Hedges.
He told Sky News: "We see absolutely no evidence for any of the charges laid against him.
"We're very concerned for his welfare.
"The UAE is supposed to be a friend and ally of Britain's. We've given them repeated assurances about Matthew. If we can't resolve this there are going to be serious diplomatic consequences, because this is totally unacceptable."
The Foreign Office did not reveal what form any possible diplomatic consequences could take, but said a number of options were available.
Mr Hunt tweeted that he had a "constructive conversation" with UAE's foreign minister and trusts he is "working hard to resolve the situation asap".
Mr Hedges, a Middle Eastern studies specialist, was said to be shaken with fear when he received the sentencing.
In an emotional radio interview broadcast just hours before her meeting with Mr Hunt, Ms Tejada said the Foreign Office had failed to take a firm stance with the UAE over his detention from the outset.
"I was under the impression they were putting their interests with the UAE above a British citizen's rightful freedom and his welfare," she said.
"I believe that they should have taken a firmer stance from the beginning, if not publicly then through their private representations. This is something I feel they failed to do throughout, really.
"They just disregarded my requests, they said it wasn't part of their job, it wasn't part of their duty.
"On one occasion one of the case workers said the Foreign Office did not have a duty of care so weren't obliged to make such representations."
Mr Hedges' family says he has been held in solitary confinement for more than five and a half months, during which his "mental and physical health seriously deteriorated".
UAE authorities said his research in the country for his thesis on security policies after the Arab Spring was a "cover" for carrying out surveillance for a "foreign agency", thought to be the UK government.
Ms Tejada added: "He was very, very scared when he was standing in front of the judge, just because we knew the possibilities of there being an arbitrary judgment were there.
"I asked him to look at me if he was feeling too nervous and he tried to do so on a couple of occasions but was asked to face the judge. And he started shaking when the translator told him the sentence.
"He actually had to ask to double-check if he heard right."
Commenting on the sentence, the UAE ministry of foreign affairs said the government would not "attempt to interfere" in the judgment.
It insisted Mr Hedges had been treated "fairly and according to the constitution of the UAE", adding: "We are proud to have a system of justice that gives everyone the right to a fair trial."
The ministry added the case had been "thoroughly investigated" and "compelling and powerful evidence" had been presented, including from his electronic devices, UAE intelligence agencies, witnesses and his own confession.
The ministry also disputed claims that Mr Hedges had been made to sign a confession in Arabic, a language he does not understand, saying he had been provided with translators.
It continued: "The crimes Mr Hedges was accused of are extremely serious. For the UAE, like all countries, protecting our national security must be our first priority.
"Under the law of UAE anyone convicted by a court has the right to appeal the decision within 30 days. Families also have the right to appeal for presidential clemency on behalf of convicted relatives.
"The UAE is determined to protect its important strategic relationship with a key ally.
"Both sides hope to find an amicable solution to the Matthew Hedges case."