A new clash over a carbon tax will shape the next election as the Greens launch a campaign to reinstate a price on carbon, challenging Labor to embrace the policy as the strongest way to reduce greenhouse gas emissions.

The Greens will vow to restore the carbon price put into place in 2011 and scrapped in 2014, telling voters the Parliament can reinstate the policy as if the scheme had never been repealed by the Coalition.

But it will drop the fixed price in the first three years of the original carbon tax and instead promise a market price linked to overseas carbon schemes.

"The Greens would seek to pick up where we would be had the scheme not been repealed, namely with the floating price," the new policy plan states.

The decision escalates the political fight over climate change after the collapse of the National Energy Guarantee under former prime minister Malcolm Turnbull, which has left the Coalition and Labor searching for policies to cut emissions.