A former foreign minister for Iraq has said that Britain has a "moral obligation" to provide direct military support in defeating the Islamist militants in the north of the country.
Hoshyar Zebari, who was minister until earlier this year, also warned that without foreign intervention Iraq risks becoming a terrorist state.
Speaking to ITV News presenter Mark Austin, he said all of the nations that invaded Iraq to oust the late president Saddam Hussain have a duty to save the country from collapse.
So far, the Government has insisted it is taking a humanitarian role in the crisis and that it does not currently envision any military involvement.
The Prime Minister confirmed earlier today that an RAF Tornado made surveillance flights over the area last night, reinforcing the US view that there are fewer refugees in the Sinjar mountains than previously estimated.
He also said that military assets - including Tornado jets and Chinook helicopters - would remain in place "to help out in the right way".
President Obama cast the possibility of any rescue mission into doubt this evening, stating that he does not expect "an additional operation to evacuate people" from the area.
While US airstrikes have set back the advance of Islamist militants, Mr Zebari said further foreign intervention was needed.
He also had this warning about the threat from the Islamic State group if they are allowed to gain a foothold in northern Iraq.