The petition to save one of Christchurch's birthing units has been boosted with support from Gemma and Richie McCaw.
The closure of St George's Maternity Centre would leave Christchurch Women's Hospital as the only primary birthing unit in the city.
The McCaws have promoted the petition on their social media channels and organisers say they've helped bump it to at least 20,000 signatures.
Samantha Gee has more.
