The Northern Irish executive in Belfast has introduced regulations that prohibit live music in indoor licensed venues in Northern Ireland.
All hospitality and entertainment venues are currently closed as part of a six-week lockdown, but Morrison is eager to challenge the rules for when they reopen.
Rice noted that the “Brown Eyed Girl” singer had been able to perform in England several times late last year before the British government tightened rules there.
He said he expected the case to be heard at the High Court within “weeks”.
Morrison was taking the action “on behalf of the thousands of musicians, artists, venues and those involved in the live music industry, said Rice.
The singer, known as “Van the Man” to his fans, has stirred controversy during the pandemic, last August reportedly urging people to “fight the pseudoscience” around Covid-19.
A month later he released at two-week intervals a trio of new tracks – named “Born To Be Free”, “As I Walked Out”, and “No More Lockdown” – containing controversial lyrics.