A Mooroolbark grandfather is fighting for life in hospital after he was bashed by a group of thugs outside his home on Christmas night.

The 50-year-old was outside his home on Esther Crescent with his wife, 25-year-old daughter and two month old grandchild when they were confronted by several youths armed with baseball bats and bars at 10.30pm at night.

Brother in law Mark said that was when all hell broke loose.

“They knocked my sister out, and had my niece – from what I understand – by the hair,” he told 3AW News.

The 25-year-old woman managed to barricade herself inside the home with her two-month-old and a toddler.

“He’s in intensive care – he’s brain dead – it’s heartbreaking,” Mark told 3AW.

In a statement, police said the exact circumstances surrounding the incident are yet to be established and an investigation is ongoing.

Investigators were told up to eight people were involved in an incident.

Anyone who witnessed the incident or has information is urged to contact Crime Stoppers on 1800 333 000.