The sequel to The Da Vinci Code is among projects expected to be hit by a writer strike in Hollywood.

The screenwriter was frantically trying to finish the script for Angels & Demons to avoid crossing a potential picket line - which is likely to occur if an agreement is not reached after the writers’ present contract expires.

The Writers Guild of America voted overwhelmingly to take strike action if a deal is not agreed.

The main bone of contention is that writers want their terms changed to include percentage of the profit which is made when their work is distributed on digital media, such as mobile phones and the internet.

Ron Howard returns to direct the next Dan Brown conspiracy theory and, along with screenwriter Akiva Goldsman, is under pressure from Sony executives to get the project ready for filming in February.

British writer Peter Morgan - who is working with Howard as he supervises the screen adaptation of the play Frost/Nixon - claims the director will be working on the two projects at once.

‘The strike is a headache for him,’ he said.

‘Angels & Demons is a huge film and they’re having to rush it through.’

The film is earmarked for release at the end of 2008.