The Foreign Office has summoned Sudan's charge d'affaires to express the UK's "deep concern" at the death sentence handed to a pregnant Sudanese woman for refusing to recant her Christian faith.

Sudanese diplomat Bukhari Afandi was called in for a meeting with a senior Foreign Office official over the case at the request of Foreign Secretary William Hague.

Meriam Ibrahim, whose father was Muslim but mother was an Orthodox Christian from Ethiopia, was convicted of apostasy and sentenced to death earlier this month.

A Foreign Office spokesman said: "At the request of the Foreign Secretary, the charge d'affaires at the Sudanese Embassy in the UK, Bukhari Afandi, was summoned to the Foreign Office today to meet political director Simon Gass.

"The political director expressed deep concern at the recent decision to sentence Meriam to death for apostasy and asked the Charge to urge his government to uphold its international obligations on freedom of religion or belief, and to do all it can to get this decision overturned."

After the sentence was passed last week, Africa minister Mark Simmonds said he was "appalled" at the "barbaric" punishment.