Labor's attempt to settle a new asylum seeker policy which would allow for boats to be turned around at high seas has been interrupted by a noisy protest within moments of the debate beginning.

Left faction MP Andrew Giles had just started talking in favour of a prohibition on turn-backs at the party's national conference when protesters mounted the stage at the Melbourne Convention Centre brandishing a large banner calling for a ban on tow-backs.

Several minutes were lost as security and party officials wrestled the protesters off the stage, prompting the newly elected ALP National President Mark Butler to call for better behaviour.