Treasurer Jim Chalmers has rebuffed a Greens offer to support a $2.3 billion clamp-down on wealthy Australians’ retirement savings, in a move that could set up a second double dissolution election trigger if the minor party does not relent.

Greens Senator Larissa Waters on Friday tied an expansion of the taxpayer-funded paid parental leave scheme to include superannuation payments in return for the minor party’s backing to lift the tax rate on superannuation balances above $3 million to 30 per cent.