Bill Shorten has rebuffed overtures from the Greens for a new pact between the two parties on climate and energy policy ahead of next year's election.

Greens leader Richard Di Natale and energy spokesman Adam Bandt wrote to their Labor counterparts Bill Shorten and Mark Butler in late August after the toppling of Prime Minister Malcolm Turnbull and the demise of his signature energy policy, the National Energy Guarantee (NEG).

Richard Di Natale, the Greens leader (left), with Labor leader Bill Shorten at a breakfast gathering earlier this year. Credit:Alex Ellinghausen

Fairfax Media understands Mr Shorten and Senator Di Natale met in Mr Shorten's Melbourne office on October 1.

The Greens advocated a pact because no single party was likely to control both houses of Parliament after the next election, arguing it was "critical" for Labor and the Greens to strike a consensus as they had during the Gillard years.