Hundreds of people took to the streets of Nelson and Blenheim on Thursday in support of the Tasman Makos who face being dropped from rugby's top division next season.
Fans of the side - an amalgamation of Nelson Bays and Marlborough - say the end of top rugby in the top of the South Island will be disastrous for the future of the game.
The New Zealand Rugby Union says financial losses running the Air New Zealand Cup are unsustainable and the competition has to be trimmed to 10 teams.
Tasman is tipped to be one of those demoted, along with Manawatu, Northland and Counties-Manakau.
A petition with 15,000 signatures supporting Tasman will be given to NZRU chief executive Steve Tew before Friday night's game against Wellington in Blenheim.