Briton Matthew Hedges has been sentenced to life in prison in the United Arab Emirates on charges of spying.
Hedges, a 31-year-old doctoral student at Durham University in the UK, has been held in the UAE since May 5 this year after he was arrested at Dubai airport.
Foreign Secretary Jeremy Hunt said he is "deeply shocked and disappointed" by the verdict.
"I have personally raised the case of Matthew Hedges at the highest levels of the UAE government, including during my visit to Abu Dhabi on 12 November. On that occasion, I spoke to Crown Prince Mohammed bin Zayed and Foreign Minister Abdullah bin Zayed.
"However, today’s verdict is not what we expect from a friend and trusted partner of the United Kingdom and runs contrary to earlier assurances.
"Our consular officials have been in close contact with Matthew Hedges and his family. We will continue to do everything possible to support him.
"I have repeatedly made clear that the handling of this case by the UAE authorities will have repercussions for the relationship between our two countries, which has to be built on trust. I regret the fact that we have reached this position and I urge the UAE to reconsider," he said.
British Prime Minister Theresa has also reacted.
She said in Parliament during PMQs: "We are of course deeply disappointed and concerned at today's verdict.
"We are raising it with the Emirati authorities at the highest level," she added.
His wife Daniela Tejada, who was present at the courtroom, said in a statement:
"I am in complete shock and I don’t know what to do. Matthew is innocent. The Foreign Office know this and have made it clear to the UAE authorities that Matthew is not a spy for them. This whole case has been handled appallingly from the very beginning with no one taking Matthew’s case seriously.
"The British Government must take a stand now for Matthew, one of their citizens. They say that the UAE is an ally, but the overwhelmingly arbitrary handling of Matt’s case indicates a scarily different reality, for which Matt and I are being made to pay a devastatingly high price.
"This has been the worst 6 months of my life, let alone for Matt who was shaking when he heard the verdict. The UAE authorities should feel ashamed for such an obvious injustice. I am very scared for Matt. I don’t know where they are taking him or what will happen now. Our nightmare has gotten even worse." she said.
Euronews spoke to his wife on October 25.
She said her husband had been finalising his PhD studies in the UAE and his thesis was focused on the impact of the Arab Spring.
He had been interviewing people from a cross-section of society, she said.
According to Durham University's website, Hedges research interests included civil-military relations, political economy, and tribalism.
Last year, he co-authored an article in an academic journal on the Muslim Brotherhood and the Gulf Cooperation Council, of which the UAE is a member.
Hedges has always denied the charge against him.
Look back at our October interview with Daniela Tejada by clicking on the player below: