For the past four months heartbroken parents Jason and Renee Cassar have done everything humanly possible to help their "spunky little man".

Joshua had just turned one when his ruptured Wilms tumour took his left kidney and part of his diaphragm.

Wilms tumour, also known as nephroblastoma, is a rare kidney cancer that usually occurs in young children.

The Mount Warrigal toddler has undergone a prolonged and intensive chemotherapy course, which is expected to continue until at least this September.

Joshua is showing plenty of courage in his battle, but the constant travel to Sydney Children's Hospital and back home is taking its toll on his parents.

His mother has opted to stay with her son when he is in hospital at all times but Mr Cassar needs to work and look after Joshua's sisters, Maddison, Charlotte and Aliyrah.

Travel costs are proving financially challenging so a group of supportive mothers' group friends have created the "Joshy's Journey" charity and are calling for support to help the family raise $20,000 to buy a new car to make the journey easier.

They are running an online auction on Joshy's Journal Facebook page from March 8 at 6pm until March 9 at 8pm.

Visit facebook.com/joshyjourneyaustralia to take part in the auction.