The case may have hit the headlines as one of the most high profile media battles of recent years, but copyright specialists are predicting the court wrangle over The Da Vinci Code could also settle some of the oldest controversies in copyright law.

The claimants, authors Michael Baigent and Richard Leigh, allege that Dan Brown's famed novel breached copyright in adapting material from their book The Holy Blood and the Holy Grail.

As such the case, which began in the High Court on 27 February, is one of the few publishing disputes to explicitly address the extent to which ideas can be protected under copyright – one of the oldest debates in media law.

"This is a real issue which has created legal uncertainty and leads lawyers to give unpredictable answers. Lawyers are looking to this case for a definitive answer," said media partner Mark Stephens of Finers Stephens Innocent.

Almost as significant will be the definition of 'substantial', relating to the amount of material the claimants need to show was transferred from their non-fiction work into Brown's novel, which is set to hit the big screen in movie form in May.

Pinsent Masons media lawyer Les Christie told Legal Week: "What is meant by 'sufficient amount' is exactly where the skill of a copyright lawyer lies – it is a test of fact and degree."

The case also promises a major boost to the profile of both sides' solicitors, neither of which is regarded as an established adviser in the publishing sector in the UK.

City boutique Orchard, fielding a team under partner Paul Sutton, is advising the claimants, alongside Hogarth Chambers silk Jonathan Rayner James QC.

Acting for The Da Vinci Code publisher Random House is the London arm of US giant Arnold & Porter, fielding a team under partner Ian Kirby and John Baldwin QC of Eight New Square.

Lawyers believe the verdict will have a major impact on other potential claims. One partner close to the case told Legal Week: "This is a landmark case, whichever way it goes, it will probably set the scene for some time to come."

Reynolds Porter Chamberlain publishing specialist David Hooper said: "Lawyers always said in the pop music world, 'where there's a hit, there's a writ', and it could be that books are heading that way."