Malcolm Turnbull is a 'wuss-bag': Marles

The prime minister has been labelled a "wuss-bag" by a senior Labor MP.

Opposition immigration spokesman Richard Marles made the sledge while talking with cabinet minister Christopher Pyne on SKY TV, who repeated the label in disbelief.

Mr Marles was taking aim at Malcolm Turnbull after he declined to front a town hall debate in Brisbane with Mr Shorten.

"The prime minister is a total wuss-bag - not showing up to the debate showed all the courage of a fleeing mouse," Mr Marles said.

Mr Pyne hit back at the statement, saying the prime minister had chose a Facebook debate to reach ten million Australians and demonstrate he is an innovation prime minister.