More than 20 projects under the Coalition's $2.5 billion Emissions Reduction Fund have failed to deliver a promised 13.5 million tonnes in carbon abatement and have been terminated by the Commonwealth over the past four years.

As the Morrison government injects another $2 billion into the fund, which now forms the centrepiece of its climate action policy, the Clean Energy Regulator also confirmed 135 projects had been revoked and taken off the fund's register and would be ineligible for future auctions.