Individual mortgage and joint deeds

Hi myself and my partner are in the process of buying our first house and the mortgage is only in my name. The reason for this is that I work for a bank and qualify for a very attractive staff rate and also he is recently self employed. His parents have gifted us around 25% of the property value and I need to know if I am able to have the house deeds in joint names to provide him with some security due to the large amount of funds given by his parents.

Can anyone help or provide any advice?

Thanks