Prime Minister Malcolm Turnbull will use his final speech before Saturday's election to call for a new era of civility in politics, saying the culture of "juvenile theatrics and gotcha moments" annoyed voters and hampered efforts to strengthen the economy.

As expectation rapidly builds that the Coalition will be re-elected, Mr Turnbull will argue that Australia's above-average growth rate of 3.1 per cent could not be taken for granted in a volatile global environment.