Notoriously, Iran doesn’t recognise dual nationality – so it won’t make a lot of difference to officials there that Crouch End woman Aras Amiri, unlike Nazanin Zaghari-Ratcliffe, has no British passport.

And at any rate, British intervention hasn't amounted to very much for Nazanin. The West Hampstead charity worker was finally granted diplomatic protection this year only to be treated even more callously than before, with (hastily withdrawn) talk of a "prisoner swap" as though she were property rather than a human being, and her rights to medical treatment again being denied.

All the same, it makes a symbolic difference for a British MP to be petitioning the foreign secretary on Ms Amiri's behalf.

It sends the message to Iran that we recognise Ms Amiri's rights and that we are taking her detention personally (and not because she is a "spy") - that, unlike Iran, we value Ms Amiri as an individual rather than a flag-bearer or a bargaining chip.

Mr Hunt must take up the challenge of Catherine West and Tulip Siddiq and respond to Iran's actions swiftly, clearly and intelligently, demanding the release of both prisoners.

And his government would do well to remember in its own foreign policy the message that the UK is now sending - that nationality is less meaningful than humanity. It is a value of which we have fallen shamefully short in recent years.

Ironically - or not, perhaps - it is also a value that Ms Amiri's organisation the British Council works to promote: that borders can be erased or diminished through cultural exchange and mutual understanding. Iran has been less than receptive to that message, shutting the Council's office in 2009. But for Ms Amiri's sake, and in her name, both Britain and her employer must continue striving for better international relations. It may, one day, save families from the pain now being experienced by the relatives of these two north London women.