Support for the Turnbull government has taken a dive amid speculation of a possible challenge by Home Affairs Minister Peter Dutton, the latest Fairfax/Ipsos poll shows.

The coalition's primary vote has dropped from 39 per cent to 33 per cent in a month, while Labor leads the government 55 per cent to 45 per cent on a two-party preferred basis.

Prime Minister Malcolm Turnbull's personal approval also took a battering, falling from 57 to 48 per cent. Bill Shorten's standing as preferred prime minister rose from 30 to 36 per cent.

The plunge comes as the Liberal party struggles to achieve internal consensus on the National Energy Guarantee, with a small group of right-wing MPs, including former prime minister Tony Abbott, lobbying against the policy.

The division is feeing speculation Mr Dutton may make a move on Mr Turnbull and challenge him for the leadership.

Liberal frontbencher Christopher Pyne said "one of the outcomes from disunity is poor polling figures".

"And the people who are trying to create disunity, of course, that's what they want," he told ABC radio on Monday.

"Then they try and feed on that poll and say 'see, we told you so'."

His colleague Simon Birmingham also blamed the rebel MPs.

"You have to recognise that when a handful of individuals decide to go out and argue against the majority - the overwhelming majority opinion of the party room - that's going to have some negative consequences," the education minister told Sky News.

Australian Associated Press