About 500 Liberal and Nationals supporters, including former prime ministers John Howard and Tony Abbott, gathered for the coalition campaign launch in Sydney.
Mr Turnbull has warned that Britain's exit from the European Union underlined the need for stable majority government.
" The upheaval reminds us there are many things in the global economy over which we have no control. Calm heads, steady hands, and a strong economic plan are critical for Australia to withstand any of these negative repercussions."
The pitch came as Labor unveiled its policy costings and budget forecasts in a bid to bolster its economic credentials ahead of Saturday's poll.
Bill Shorten used a second campaign launch in Brisbane to also denounce Mr Turnbull's claims about his government's stability.
" No amount of waffle dressed up as oratory can disguise the fact that my opponent is, and always will be of his party. A hostage of extreme right-wing ideology. Mr Turnbull says this is the time for stability. But you cannot have stability without unity."
The Australian Greens also launched their campaign in Melbourne (sun).Greens leader Richard Di Natale says the minor party could win a few seats in the lower house.
" It is the Australian Greens who have been leading and shaping the national debate. Increasingly winning support for our courage, for our vision, for our willingness to stand up to those vested interests. Our vote is growing because people understand that innocent people fleeing torture and persecution coming here, seeking protection, can make a contribution to the nation and that we can meet those challenges through a little more compassion, creativity, and cooperation."
