Dr Evan Harris is hoping his Private Member’s Bill is passed and ends centuries of “discrimination”.
The proposed legislation would also allow a monarch’s daughter equal claim to the throne rather than being superseded by a younger brother.
The Bill would mean Britain’s Princess Royal, Princess Anne — Queen Elizabeth’s second oldest child — would be fourth in line to the throne behind Prince Harry, instead of coming below the Duke of York, Earl of Wessex and their children.
Over the years royal brides have left their Catholic faith in order to ensure their husbands can succeed to the throne. The wife of Peter Phillips, Queen Elizabeth’s grandson, did just this before their wedding last year.
The Bill had its first reading in parliament yesterday but is guaranteed a second reading debate in March. If it passes this hurdle it will have a day for its final report stage.