Labor’s battle to win Senate support for its climate change targets could continue for another two months following confirmation the legislation will not go before the Senate until September, and the Greens saying negotiations over their key demand were “not even at square one”.

As the Labor caucus gave its approval to the legislation to be introduced to parliament on Wednesday, Greens leader Adam Bandt said the Greens were prepared to shift to crunch a deal, but there had been limited progress on his condition that there be a moratorium on all new coal and gas developments.