Barnet-based Iranians have won the support of 220 MPs in their fight to prevent their relatives in Iraq being expelled from a resistance base back to Iran, where they face persecution.
Five thousand Iranian members of the People's Mojahedin of Iran (PMOI) - which is listed as a terrorist organisation by the US - were due to be sent back to Iran from Iraq by the end of last year, according to the Iraqi Governing Council.
The move worried Iranians in Barnet such as Azadeh Hosseini, 19, of Mill Hill, who said their relatives in the PMOI would almost certainly face imprisonment, and even torture and execution, if sent back to Iran.
The International Committee of the Red Cross has confirmed that such a move would break the Geneva Convention, which considers the PMOI members to be civilians, because they did not take part in the US-led war in Iraq.
It states that they cannot be deported against their will, particularly to a country where they may be persecuted.
Now the MPs, alongside 85 members of the House of Lords, have called for the PMOI members' safety to be guaranteed and for the PMOI to be removed from the terrorist list.
Dr Rudi Vis, MP for Finchley and Golders Green, added his support, saying he would be extremely concerned for the welfare of the PMOI members if they were sent back to Iran.
Ms Hosseini said she and other UK-based Iranians were trying to send news to their relatives via the Red Cross organisation.
"Over 300 MPs and lords are supporting us," she said.