Afghanistan's parliament has written to Iran calling for a delay in the deportation of thousands of Afghan refugees until after the winter.
Thousands have been returned from Iran since April
In an open letter, the MPs have urged the Iranian president, Mahmoud Ahmadinejad, to intervene.
Iran says there are hundreds of thousands of Afghans who are in the country illegally, alongside huge numbers of registered Afghan refugees.
Tens of thousands have already been repatriated since 21 April.
Teheran says there are plans to return many more.
In the letter, carried by Afghanistan's state media, the MPs have urged Mr Ahmadinejad to stop the deportations until the end of the harsh winter.
The UN has warned that Afghanistan does not have the resources to cope with such an influx and has called for an end to forcible repatriation.
There are about 920,000 registered Afghan refugees in Iran, which took in hundreds of thousands of Afghans during the country's years of war.
It has been deporting refugees for some time, but correspondents say that never have so many been moved in so short a space of time.