Turnbull job 'quite secure': minister

Liberal frontbencher Arthur Sinodinos has rejected suggestions Malcolm Turnbull is on thin ice with party colleagues.

The coalition has trailed Labor in most of the polls since last year's election, which reduced the coalition to a one-seat majority, and there has been speculation the prime minister is on borrowed time.

"I think his leadership is actually quite secure - and I think that the honesty he's shown in tackling some difficult issues since he got the job has been fantastic to watch," Senator Sinodinos told the National Press Club in Canberra on Wednesday.

He pointed to the way in which the government had wound back tax breaks on superannuation for the wealthy as a sign Mr Turnbull was prepared to make hard decisions.

"We can say to the community, when we're asking you to do something we're not exempting the big end of town, or our own base. I think he deserves real marks for that."

Asked whether the government was preparing the ground to dump its promised tax cuts for big business, another Liberal constituency, he said: "We promised it at the election. What is going on here? Can't we keep our promises?"

The industry minister said the tax cuts were "complementary" to his work in the area of injecting science and innovation into every aspect of business and government.

The government has been unable to reach a deal with the Senate crossbench on the corporate tax cuts but is expected to get agreement on cuts for businesses under $10 million turnover.