Removing Joint owner from Mortgage?

My partner jointly owned his property with his brother, his brothers girlfriend moved in and my partner wanted to sell the property or be bought out, as they couldnt afford to do either and he was family my partner agreed to move out and for his money to be paid to him when the property is sold in about 2-3 years time. His brother is apparently getting the mortgage on his own, but 2 months down the line my partner is still on the mortgage title as joint owner because the mortgage provider has not offered the mortgage yet. He is using the same provider which they both used and has claimed that there has been a delay in getting it offered because an ex girlfriend has applied for a loan about 9 months ago when she lived at the property…. i do think he is lying about this as this would surely come up on the credit check he would have had immeadiatley when applying for the mortgage wouldnt it??? im worried that he has been declined the mortgage and is stalling my partner as long as he can as he would therefore have to sell the property and move. My partner doesnt want to rock the boat with his family by questioning him further so i wanted some advice to weather you think this is a valid reason the mortgage offer has been going on for over 2 months???? He has had problems with his brother not paying his share of the mortgage in the past and not telling him about it until they got a letter in the post… luckly my partner had been paying enough to cover the mortgage but his brother hadnt paid his half for 4 months in a row - im terrified something like this might happen and without my partner not conributing the property might get into serious arrears and then this will effect our own future.. Please help!

Quick Property Sale