One MP said Mr Turnbull had effectively pre-empted discussion among MPs who are nervous about an increase in the GST during the meeting, telling colleagues - as he has said publicly - that no decision has been taken on whether to proceed with a rise in the consumption tax as part of its tax reform package, and that everything remained on the table. Prime Minister Malcolm Turnbull, pictured with wife Lucy Turnbull on Tuesday morning, has told colleagues a double dissolution election remains a possibility. Credit:Andrew Meares The government's tax reform package would go to cabinet later this year, Mr Turnbull said, and then the party room for discussion. That same MP said there was considerable disquiet, though it did not raise its head on Tuesday, about the prospect of a GST rise among two groups of backbenchers - those who strongly favour small government and those are scared of losing their marginal seat. "It's fine that all options are on the table, but the backbench is increasingly unified about this," the MP said.

"Scott [Morrison] is determined to raise the GST, he wants to be the Treasurer who delivers big reform...we are relying on the PM to listen to the backbench." "I think Malcolm has an open mind on this." Liberal Party federal director Tony Nutt also addressed the party room meeting about the 2016 election. Mr Nutt told MPs it was important, in the election year, to sharpen the distinctions between the two major parties and that the Coalition had to "beat the French", a reference to the defeat of Napoleon at the battle of Waterloo in 1815. The federal director said the Coalition needed to "set the terms" of public debate about key election issues such as tax reform and warned if they did not, Labor would.

Mr Turnbull's comments tally with previous public commentary from the prime minister about the timing of the election. On Friday, Mr Turnbull said "there is a budget in May...and there will be an election, you know, all other things being equal, in August, September, October". If an election is called before July, a double dissolution must be held. In a double dissolution, all 76 senators face voters which means just half a normal quota is required, which increases the chances of minor parties winning seats - an outcome the government would not look favourably on. The two pieces of legislation the government wants to push through are bills that would re-establish the Australian Building and Construction and Commission - this bill is due to re-enter the lower house on Tuesday morning but will face difficulty passing through the Senate, having been knocked back once already - and a bill to establish a Registered Organisations Commission that will strengthen union governance requirements.

This bill is already a double dissolution trigger. Employment Minister Michaelia Cash will this week allow crossbench senators who blocked the ABCC legislation the first time around to view the confidential volume from the Heydon royal commission's final report in a bid to win their support for the bill. One Labor and one Greens MP were also invited to view the document under strict condictions, but refused. Greens MP Adam Bandt accused the government of "trying to threaten members of the crossbench". "You can't ask people to vote on a piece of legislation unless you are going to put all the facts in front of them," he said.