reinstate ILR status

[kingdom]

Hi
My father is an Iranian Citizen whom has been married to my Scottish mum for over 26 years. My father lived in Britain for 17 years on ILR before starting a new life in Iran with my mother. He has lived in Iran for the past 8 years without fully being aware of the validation conditions of his ILR. Him and my mum have tried to come back to UK again, particularly for health reasons and the degradation of my grandfather's health (my mum's father) only to find out that his ILR expired 3 years after leaving GB. My mum is really keen on coming over to Britain for various reasons but there is no way for her to leave my dad (in his poor health) alone for 6 months to get things in order for him to join on a new ILR. I was wondering if there is anyway he can restore his previous ILR seeing as he used to have one for 17 years and also the fact that had he known the conditions of ILR when leaving the country, he would have made sure to take the necessary steps in order to maintain his immigration status.

Hope you can help me on this matter,

[kingdom]

I have actually looked this up now and what I am talking about is technically known as "returning resident". Would my father be eligible for this? On what grounds should he proceed?

[vinny]

SET9.5 Exception to the two year rule for those who have strong ties to the UK.