Disability Minister Bill Shorten has warned that a Coalition proposal to delay the passage of the government’s NDIS overhaul by eight weeks will cost taxpayers $1.1 billion by leaving participants free to overspend.

Mr Shorten slammed the Coalition and Greens for potentially teaming up to send the government’s Getting the NDIS Back on Track legislation to a second Senate committee process, saying the relevant senators would not even be in the country for two of the eight weeks because they had a “junket” planned in Brazil.