A British-Iranian woman jailed in Iran for allegedly plotting to topple the government has lost the final stage of her appeal.
Nazanin Zaghari-Ratcliffe was arrested by the Revolutionary Guards at Tehran Airport on 3 April while visiting family in Iran with her two-year-old daughter.
Iranian media have said she was convicted of plotting the "soft overthrow" of Iran's clerical establishment, a claim she has denied.
She was sentenced to five years' imprisonment in September and lost an appeal against her sentence in January.
Her husband Richard Ratcliffe said the appeal to the Supreme Court was her last legal opportunity to challenge the sentence.
"As her husband, I can say Nazanin is innocent until I am blue in the face," he said in a statement.
"I have spent a year doing it. But it makes a clear difference that the Government hasn't. It indulges the whispers."
While the Foreign Office has previously expressed "deep concern" over Ms Zaghari-Ratcliffe's sentence, it has stopped short of calling for her release.
Both Prime Minister Theresa May and Foreign Secretary Boris Johnson have raised her case with their counterparts in Iran.
A spokesman for the Foreign Office said: "We are deeply concerned by reports that Nazanin Zaghari-Ratcliffe's Supreme Court appeal has been rejected, while Iran continues to refuse the UK access to her.
"The Prime Minister and Foreign Secretary have both raised Mrs Zaghari-Ratcliffe's case with their counterparts in Iran. The minister for the Middle East, Tobias Ellwood, has spoken to his opposite number repeatedly to express our concern.
"We have been supporting Mrs Zaghari-Ratcliffe's family since we were first made aware of her arrest. Mr Ellwood has met her husband in London and her family in Tehran to assure them that we will continue to do all we can for her.
"We continue to press the Iranians for access and for due process to be followed, and are ready to help get her daughter back safely to the UK if requested."
Iran does not recognise dual nationalities, meaning those detained cannot receive consular assistance.
Ms Zaghari-Ratcliffe's daughter, Gabriela, is being looked after by family members in Iran after her passport was seized.
Kate Allen, director of Amnesty International UK, said the decision was "bitterly disappointing" for Ms Zaghari-Ratcliffe.
She said: "Lest we forget, Nazanin is a prisoner of conscience who shouldn't be behind bars at all, never mind for five years.
"It's now vitally important that the UK Government start doing far more on Nazanin's case.
"Ministers have got to step up and demand that Nazanin is released.
"Pending her release, Nazanin should also be given much-needed medical treatment outside the prison she's being kept in."