The ethical bar for Ministers may now be set too high, the Premier says, after his controversial Treasurer and Transport Minister, Troy Buswell, came under pressure for helping to get his son an appointment for a driving test.
It emerged on Monday Mr Buswell had tasked his office to ring the Department of Transport to arrange a driving test for his son.
They succeeded in getting an appointment in October 2012, on a day when no regular driving tests were scheduled in his hometown of Busselton, according to the public sector union.
Opposition transport spokesman Ken Travers said Mr Buswell's actions were a breach of the Ministerial Code of Conduct and he should be sacked.
But Colin Barnett said Mr Buswell's son had received no preferential treatment, and hit back at his Minister's critics.
"The bar is too high now - any father, any mother is going to help out their kid to get a driving test," Mr Barnett told radio Nova 93.7.
"There was nothing improper or wrong.
"He's a dad, it's his son. Lots of people ring Troy's office to voice that frustration and Troy's office will ring through and make sure they get a response.
"Troy's son was treated no differently than anyone else."
Mr Buswell's office revealed figures showing his staff had contacted the Department of Transport 51 times last year on behalf of people struggling to book driving tests, including eight requests from Labor MPs and 19 from coalition members.
Mr Barnett said after his experience, Mr Buswell had also tried to ram home the issue to senior transport officials.
"Troy told me he has got some of the senior people from Transport, put them in the boardroom and told them to ring up and make an appointment for a driving test."An hour later, no response - so I think he made the point."