Opposition Leader Bill Shorten has unveiled the details of his controversial asylum seeker plan to the ALP faithful, insisting that boat turn-backs keep faith with Labor values.

Mr Shorten has staked his leadership on the policy, arguing a future Labor government must have the option of turning boats back to Indonesia when it is safe to do so. But the policy reversal has drawn heavy fire from the party's Left faction.

The Left met for an hour on the sidelines of the ALP national conference on Saturday but has not yet decided whether it will move an amendment to the party's draft platform that would explicitly prohibit turn-backs.