The Labour MP for Hauraki-Waikato says it is up to John Tamihere to prove himself, now that his application to rejoin the party has been approved.
The former Labour Government minister was censured in 2005 for making offensive comments about women and homosexuals.
His bid to rejoin the party has been seen by many as a stepping stone for a return to Parliament as a Labour MP.
Nanaia Mahuta says a lot of people will be watching Mr Tamihere closely, and he needs to watch himself.
She says she has a number of concerns about his previous behaviour, and it is now up to him to demonstrate that he upholds the values of the Labour Party.