The Abbott government has re-introduced a controversial freeze on granting protection visas to refugees who arrive by boat on the eve of a High Court challenge on behalf of a 15-year-old Ethiopian boy who is being denied a visa.

The freeze was introduced, but quickly revoked, late last year under threat of legal challenge, but re-introduced without explanation on Tuesday, prompting outrage from refugee advocates.

Says the decision to reinstate the visa freeze is "extraordinary", and that it lacked any rational basis in policy or law: Refugee lawyer David Manne. Credit:Stuart Walmsley

The lawyer leading the challenge, David Manne, described the decision as ''extraordinary'', saying it lacked any rational basis in policy or law.

But a government spokesman defended the move, saying the freeze on visas for boat arrivals would enable the government to deliver on its promise of at least 11,000 visas for those taken from refugee camps around the world.