Labor and the Coalition appear on track to bank as much as $140 million in public funding as part of a major overhaul of election laws, after the major parties shut out the crossbench to cap political spending and improve donation disclosure rules.

Special Minister of State Don Farrell engineered a deal with the Coalition on Wednesday, paving the way for the first major shake-up of electoral laws since the Hawke government. But teal MPs lashed the deal, saying they will seek to use the balance of power after the looming election to overturn it.