Professor Rebecca Probert of the University of Warwick's School of Law, who has written a book entitled 'The Rights & Wrongs of Royal Marriage' said the UK royal marriage law is in its most confused state for centuries.
He said William and Middleton's wedding could be the last royal marriage not to face major legal complications.
Professor Rebecca, an expert in current and historical marriage law, says "The laws which regulate royal marriage are not fit for purpose in the 21st century, an age when human rights and free choice are valued."
He said that files in the National Archives show that previous governments have been aware of all of these problems and absurdities of royal marriage law, but have left them for future generations to tackle.
"It's only through good luck, rather than good law, that William and Kate's wedding is free of these issues - this could be the last royal wedding to avoid major legal complications if the law is not resolved," he said.
Professor Probert's research outlines the contradictory legislative and legal mess that constitutes the last 300 years of Royal marriage law, and how that mess potentially became ten times worse when it was brought into shuddering contact with the Human Rights Act as a consequence of the wedding of Charles and Camilla.
"Nobody knows for sure how the Human Rights Act might apply to the rest of the law on royal marriage. Strasbourg judges might decide that it is discriminatory for royals to be unable to marry without the Queen's consent, or to have to choose between love, religious faith and duty.
"The law has become so confused that no one can agree on how many people need the Queen's consent to marry - it might be just a handful of aristocrats in Scotland and Germany, or an unknown number of people throughout the world who can trace their descent from King George II," he said.