THE Opposition Leader, Tony Abbott, sought yesterday to defend his party's renewed policy of turning back all asylum boats at sea as the approach was attacked by the United Nations High Commissioner for Refugees, Indonesian authorities and a former naval chief as dangerous and breaching international law.

Expressing alarm at the Coalition's border protection stance, the UNHCR regional representative, Richard Towle, said: ''Any such blanket approach would potentially place Australia in breach of its obligations under the refugee convention and other international law obligations, and - as past experience has shown - is operationally difficult and dangerous for all concerned.''

"The navy has done it safely before" ... Opposition Leader, Tony Abbott. Credit:James Alcock

Indonesia's police also questioned whether Mr Abbott's policy of using the navy to turn boats laden with asylum seekers back to Indonesia contravened international law, amid widespread disquiet in the country about the opposition's hardline position.

''As far as asylum seekers go, they fall under international law,'' said Saud Usman Nasution, the chief spokesman for Indonesia's national police. ''You can't turn them away. You have to hand them over for processing to UNHCR, just like Indonesia. We don't turn them away, we hand them to UNHCR for processing.''