The Australian Taxation Office will receive a $6 million upfront payment to wipe out almost half of its claims against collapsed building giant Grocon, according to a revised rescue plan proposed by property scion Daniel Grollo.

The sweetened offering is part of an amended Deed of Company Arrangement which Mr Grollo hopes will be supported by creditors when they reconvene next Thursday to vote on the future of the 88 collapsed Grocon companies that make up the majority of the group.