Australia Post boss Christine Holgate is resisting pressure to quit over revelations she purchased luxury watches for senior executives who secured a controversial banking deal, instead temporarily standing aside during an investigation.

Prime Minister Scott Morrison ordered the independent review after revelations $12,000 worth of Cartier watches were purchased for staff behind a deal with Commonwealth Bank, Westpac and the NAB to improve services at Australia Post outlets, saying he was appalled and shocked at the "disgraceful" spending.