Foreign Office minister Alistair Burt has raised the case of a woman sentenced to death for adultery in Iran with the country's ambassador to the UK.
The fate of Sakineh Mohammadi-Ashtiani was among a number of human rights issues discussed during the meeting with Rasoul Movahedian.
An international outcry saw a sentence of stoning lifted on Ms Ashtiani, a 43-year-old mother of two, but she could still be hanged.
Mr Burt said the UK would continue raising human rights issues with Tehran and warned that "international scrutiny will not dissipate".
The meeting also covered the jailing of seven Baha'i leaders and the case of 18-year-old Ebrahim Hamidi, facing execution for alleged homosexuality offences.
A Foreign Office spokesman said: "The minister discussed a range of cases, including the ongoing Sakineh Mohammadi-Ashtiani case, the trial of the seven Baha'i leaders, and the sentencing of Ebrahim Hamidi.
"These cases are indicative of a continued unwillingness by Iran to follow even its own judicial standards and due process.
"In each case, the minister made clear UK concerns, and urged Iran to fulfil its international obligations, as well as its responsibilities to its own citizens under the Iranian constitution."
Speaking after the meeting, Mr Burt said: "I hope Iran recognises that international scrutiny will not dissipate with time - the British Government is committed to raising these issues regularly and ensuring that those unfairly persecuted in Iran are not ignored."