In any other job, you might just write it off as a bad week. But when you're a first-term Prime Minister in the second month of an election year, a bad week is something you can't afford to have.

You certainly can't afford to have two bad weeks in a single day which is what happened to John Key.

On Wednesday he came under fire over the purchase of 34 BMW 7 Series limousines (showroom price $200,000 each, but obtained at a heavy discount) to replace the fleet bought by Helen Clark's Labour-led administration in 2008.

And on the very same day, asked in Parliament to comment on Salvation Army reports that there was a high demand for their food parcels, Key said those who resorted to such charity had made "poor choices".

"The bulk of New Zealanders on a benefit do actually pay for food, their rent and other things," he said. "Now some make poor choices and they don't have money left."

Key's history so far suggests that he does not have a tin ear for public opinion, so such an unvarnished utterance suggests he is either callous, injudiciously plain-spoken or both. It does not much matter anyway: it's how it looks that counts and, in both the BMW and the food-parcel issue, it looked and sounded bad.

Key said that he could not take responsibility for a contract "that was entered into by the previous Labour Government [and] wasn't brought to my attention", which had the ring of plausibility about it until Labour's Trevor Mallard unearthed a July 2010 report on Ministerial Services' budget which outlined the plan to buy the new vehicles and would have been provided to Key before the deal was signed.

Even that can be seen as understandable. We don't expect Key to read every report that comes through his office. But what we do expect from a Prime Minister is leadership. And in this matter Key's leadership has been shown to be woefully wanting.

The country is emerging from - or perhaps still in - a deep recession and people are hurting. A leader would have long ago impressed on every bureaucrat that austerity is the order of the day and that any spending decision that had the whiff of luxury about it should be flagged for ministerial scrutiny.

The BMW purchase would thus have been brought to his attention - and at least postponed, if not cancelled altogether in favour of a much more modest marque of motor.

It is idle for Key's spokesman to crunch accountant's numbers and point out that a three-year replacement cycle is the most cost-effective. The dollar amounts - the limos would cost only $6.8 million even before the bulk discount and the sale of the old fleet - are relatively small.

But politicians know that substance matters less than appearance, particularly in our image-saturated age. Being chauffeured in $200,000 cars while people struggle to buy groceries is a bad look.

The same goes for the "poor choices" crack. We've all come across beneficiaries whose spending was questionable but the vast majority are trapped in a poverty cycle not of their making and the PM's dismissive comment was that of a man seriously out of touch.

In making it plain that he won't stay in politics if he loses the election, Key has displayed an insouciance that may be admirably forthright but is politically risky.

The face he showed to the country this week was that of a man who didn't give a stuff what people thought. It may be one that his colleagues and National supporters hope he will not be revealing too often.