"It's obvious" some Coalition MPs don't support Prime Minister Malcolm Turnbull, cabinet minister Christopher Pyne said, as frontbenchers flew into Canberra to shore up support for the National Energy Guarantee and put leadership speculation to rest.

The Minister for Defence Industry acknowledged the open dissent within the Coalition on before a high-stakes cabinet dinner at Parliament on Sunday night.

"There are some people who don’t support the current leader and that is quite obvious," he said.

"The overwhelming majority of my party room are 100 per cent behind Malcolm Turnbull as is the cabinet. We have the right policy mix and if we are united we will win the next election."