The group is having its ideas modelled by a private consultancy and believes it can identify as much as $15 billion in credible savings to fund income tax cuts and a "modest" business tax cut. Malcolm Turnbull is serious about holding a double dissolution election in early July if he can make it happen. Credit:Alex Ellinghausen It comes as Mr Turnbull and his Finance Minister, Mathias Cormann, continue to discuss the unorthodox move of bringing forward appropriation bills in Parliament to before the May budget in order to keep a double-dissolution election option open without risk of the government running out of money to pay public servants. Fairfax Media reported earlier that informal discussions had been held about bringing forward budget day, but the latest thinking is believed to favour the early introduction of the appropriations - also called supply bills - which would clear the way for a snap poll to be called either before the budget or immediately after. Proponents say there is no legal problem with appropriating funds prior to the budget but admit the move would be tantamount to admitting an early election call was imminent.

The $15 billion figure is a similar amount of money that would have been available to spend after a GST rise to 15 per cent, which would raise about $35 billion, and the payment of compensation to low-income earners. The group of Liberal economic dries are, in particular, determined to kill any change by the Coalition - such as a dollar limit on the amount that can be deducted - to negative gearing because in the words of one MP, "why would we attack Mum and Dad investors?" "There is growing concern on the backbench about our position on negative gearing. We need to address the expenditure side of the budget instead," one MP said. "This is about finding sensible changes that ensure that the attack on Labor's negative gearing policy isn't undermined." Crucially, the group believes it can still convince the Prime Minister to not make any changes to negative gearing and set up a straight political fight with Labor over the issue, following the ALP's release of a policy that limits negative gearing to new properties only and reduces the capital gains tax discount.

Fairfax Media reported on Thursday that the government is inclined to proceed with a policy that would limit, but not eliminate, negative gearing deductions. "We hope the PM will land on the view of having an unequivocal position on negative gearing, and we are pulling the levers to make sure he lands there," says one. "We are battling Scott [Morrison] on this, but he won't make the final call". Instead, the MPs would like to see the Coalition adopt a scaled-back version of Labor's planned hike in tobacco excise. The Labor plan is designed to raise $47 billion over 10 years, whereas under the plan being considered the Coalition would look to raise about $25 billion over 10 years, or an average of about $2.5 billion a year.

The package of measures is also said to include about $6 billion in revenue raised through changes to super tax concessions. The government has already said it is looking at the entire super system and a crackdown on parking pre-tax income in super accounts is in prospect. About $3 billion in revenue would come from tightening the rules on personal income tax deductions, a plan Treasurer Scott Morrison is already considering. Eliminating deductions completely would raise between $5 billion and $6 billion but is seen as political unpalatable. Another $3 billion to $4 billion would be found through smaller, so called "rats and mice" savings, a member of the group said.

Fairfax Media reported on Thursday that the Turnbull government is set to adopt a "minimalist" approach to tax reform. Follow us on Twitter