Two-hundred-and-fifty Auckland bus drivers face redundancy following a change of bus provider in South Auckland.

NZ Bus and Howick and Eastern Buses have lost their contracts for the service.

Auckland Transport has chosen to make Ritchies and Go Bus its preferred provider instead.

First Union General Secretary Robert Reid said the bus drivers at NZ Bus and Howick and Eastern Buses could lose their jobs.

He said even if they do secure a contract with Ritchies or Go Bus, they're likely to be paid much less than they're paid now.