This week could be seen as the defining moment of the 2015 election. The week that the true nature of the election made itself clear. Whether it is going to be an election based on policy or frippery - a tax avoidance or a pink bus election.
If the pink bus wins out then that will cost Labour at the polls. There are always silly election stories that fill the space that the media has at its disposal. But just like the earlier 'snob' story from the Rochester and Strood by-election, it is being used to play on wider feelings about the Labour Party and its attitudes.
The story is being used to reinforce the idea that Labour is not running an effective campaign. That the leadership is not united and that there is a lack of control over decisions, messaging and, as a result, the campaign itself. Ed Miliband's personal standing is not strong anyway, either amongst his colleagues or in the country at large, so it won't take much to really hobble the campaign.
There has been speculation that the bus was imposed and/or that Harriet Harman chose the colour and now that Harman, a champion for women's right for her entire political career, is involved in a 'sexism row'. She vehemently denies the comment attributed to her.
Others claim that campaigning to get women to vote in the election is a good idea undermined by its execution. The sight of the pink bus arriving in Watford did have the faint whiff of a 1970s sitcom about it.
It is early enough in the campaign that Labour can do something about it. But if such incidents continue then the party can quite be accused of failing to hear the warning klaxon. A few more such incidents and the leadership looks accident prone, the campaign starts to fall apart, whispers and sniping are heard and then the anonymous briefings start to surface. That becomes the election issue.
What Labour needs is a tax avoidance election. An election based on policies and ideas that allow Miliband to champion the cause of most people. There is no doubt that the Conservatives are troubled by this line of attack. It reinforces the perception of them sticking up for rich businessmen - the complete opposite of 'we're all in this together'.
Even if the focus is on 'real' policies, that does not mean there will be a complete move away from personal attacks. Arguments over whether Miliband has 'played the man, not the ball' over HSBC and whether he himself benefited from a tax avoidance scheme, a claim dismissed as a 'straightforward lie', are used to smother the issue.
Miliband will be much happier with his interview with ShortList magazine even if the accompanying photos could best be described as 'awkward'.
The Conservatives, in particular, will be going all out for a pink bus election. It would undermine Miliband and show that Labour cannot even manage the most straightforward of issues, let alone deal with the big issues of the economy and the deficit.
Labour instead will want some big themes and areas of policy divergence to take hold. January saw an absolute focus on the NHS and now we have moved onto tax evasion. Labour, it has to be hoped, will appreciate that they could suffer collateral damage along the way. Examples will be dug out from the archives and the financial position of current shadow ministers looked at. However, once on this path Miliband simply has no choice but to stick to it. Even if it goes quiet for a while, it will come back nearer to voting day.
There is no doubt that this will mean a dirtier election and a more personal election with all the parties looking to make whatever capital they can, through whatever channels they can. Reports that the Conservatives will use YouTube 'attack ads' only add to the feeling that vitriol will win out.
So whether we end up with a pink bus or a tax avoidance election is down to the media, social media, funds and members and campaigning.
Success for Labour looks like a tax avoidance approach; success for the Conservatives looks like a pink bus.