Liberal hopeful Dave Sharma has demanded the Coalition do more to tackle climate change, arguing Australia must put itself in a "credible" position to convince other countries of the merits of stronger international action.

In a major speech designed to separate himself from the Liberals ahead of a rematch against Kerryn Phelps in the seat of Wentworth in May, Mr Sharma will suggest his diplomatic skills could be useful in convincing US President Donald Trump to rejoin the Paris Agreement.

Liberal candidate Dave Sharma has tried to separate himself from Coalition conservatives on climate change. Credit:James Alcock

Just a day after Prime Minister Scott Morrison announced he would reboot the Abbott-era Direct Action scheme through the rebadged Climate Solutions Fund, Mr Sharma will tell an audience of Coalition environmentalists that Australia "should be doing more to address climate change".

In particular, Mr Sharma - a former ambassador to Israel - will say Australia should "be more ambitious and invest greater effort" into ensuring other countries meet their commitments and "raise the level of ambition over time", beyond the 2030 Paris targets.