But thing is, they are not inserting themselves. They didn't approach the IMF with "Hey, we know Miftah committed XYZ to you, but we are just letting you know that he was lying and we won't do any thing that was asked". They approached Miftah with the details and expressed the challenges they had. Now if KP cannot even talk to the finance minister regarding the difficulties they face in completing an agenda item that was previously agreed upon, then what can they talk about?
The terms were changed though. When they signed the letter, Miftah committed that the outstanding issues would be resolved, and on that conditions KP committed to a surplus. When that commitment does not get fulfilled, then what?
Take the following scenario. You ask me to build a house in a month, and committ to me that I will get additional material for the house completion on the 15th day. But the day comes and you do not keep your end of the bargain and the additional material comes after 25 days. Would it be fair for you to still ask me to keep to the 30 day deadline? And I cannot raise my concern with you, that you did not keep your end of the bargain?
To cap it off though, from what little I have read and heard from media sources (DAWN, Shahbaz Rana) and from those I know in real, everyone agrees that the letter was inconsequential to the IMF decision and this was just political point scoring by N. It was simply an internal matter within Pakistan.