I think I've got it. It's to do with the fact that in increase in interest on an interest only mortgage affects £100k throughout the term whereas on a repayment mortgage it affects a steadily reducing balance, hence the smaller increase on a repayment mortgage

 

pslewis - I hope you're going to come back and admit you are wrong, and now crawl under a stone and hide!!!

 

As I said, the interest payment on an Interest Only and Repayment mortgage is the SAME if the SAME amount is oustanding!!

That remains a FACT - I was ignoring any declining amount, as we were talking a £100k mortgage, at ONE point in time!!

Pete