A Sri Lankan asylum seeker on a bridging visa is fighting for his life after dousing himself in petrol following a decision by the Australian immigration department to deport him back to Sri Lanka.

The man, whose first name is Janarthanan and who is in his late 20s, was on a bridging visa and had been working as a cleaner in Sydney's inner-western suburb of Balmain.

The Tamil asylum seeker, who had been living in Australia for at least 18 months, was this week told by the department that his application for a permanent protection visa had been denied and he would have to return to Sri Lanka, the convener of the Tamil Refugee Council, Trevor Grant, said.

On Wednesday night Janarthanan doused himself in petrol and set himself alight shortly after 8.30pm near the shipyard in Balmain, causing severe burns to 70 per cent of his body.