Remortgage additional borrowing > 80% LTV

I am looking to remortgage and secure some additional borrowing.

Based on the value of house and existing mortgage I come in at 78% LTV. However I want to borrow an "additional amount" which brings the LTV up to 85%.

Does anyone know of any providers who might consider my application? I know that Halifax and Nationwide will only go to 80% in this scenario.

Thanks in anticipation :)