One month ago, the chiefs of a million businesses and charities had some good news directly from No 10. But some of them were being deceived.
You can just imagine their excitement. A letter arrives in the post. Gosh, it's from the prime minister! The paper is headed '10 Downing Street' and David Cameron's signature is squiggled at the bottom. How these employers' hearts must have been fluttering.
It's not the PM's actual handwriting – it's printed, of course. And that isn't the only thing a little bit fake about this letter.
But the news it contains sounds good. Cameron is writing to confirm details of the national insurance break for businesses, which provides a reduction of up to £2,000 for each employee. A simple tick on payroll software is enough to claim the discount. "This means £2,000 cashback on the cost of jobs that you can choose how to spend," the prime minister wrote. "I hope you will consider using it to take on more employees."
Among those receiving the letter are the employers of domestic staff. One hundred years ago, 'domestic staff' might have just been for the very rich. Not any more.These days all sorts of people who need childcare: nurses and police who do shift work, and those working antisocial hours, and many other working parents. Then there's those who need to employ carers, too.
These are ordinary people who will have been delighted at receiving the letter from the prime minister. I spotted one of these people on Facebook responding to the news. She wrote: "Nice one Mr Cameron!"
Like many others, she should never have received that letter. For the government's policies weren't giving her any such break at all.
The public often suspect leading politicians of promising one thing and then, at some stage in the future, reneging on that pledge and wriggling out of it.
No such equivocation here. This was a case of being handed some good news – and then having it ripped away from you.
When you ask the Treasury about it, they explain in careful tones that the government's primary commitment is towards supporting businesses by helping them cut the costs of employment.
"Available to businesses and charities across the UK, the employment allowance will support those aspiring to grow by hiring their first employee or expanding their workforce," a spokesperson explains.
"Individuals employing someone for personal, household or domestic affairs – such as a nanny – will generally be excluded from the employment allowance, as they are neither a business nor a charity."
Sorry, they're saying. Tough luck. You're not a real business.
It's a point which has been firmly dispatched in an open letter to the PM from a group of 65 dismayed parents who contacted the firm Nannytax, which helps parents who employ nannies get the sums right on their payroll.
Their point is simply put: "The thing that we all have in common is that employing a nanny makes it possible for us to continue working and contributing to the economy.
"We think it is shocking and unacceptable that domestic employers are excluded from this scheme."
It gets worse. Excluding nanny employers, they argue, effectively means parents are being encouraged to buy into the "flourishing black market on nannies, where cash in hand, tax-free payments are commonplace".
Nannytax clearly has a business case behind such an argument – it is as firm an enemy of this particular black market as the taxman.
Still, its point is a strong one. Downing Street was asked for a response to the letter, but has not so far provided one. If it does, I'll reproduce it here.
In the meantime, the lack of a response seems unsurprising. The likelihood is an embarrassing administrative error took place. The letter should never have gone out to employers of domestic staff. Some civil servant, somewhere in Whitehall, has probably had their wrist firmly slapped.
Working parents, though, deserve to feel wronged by No 10. If you're going to take the political credit for this stunt –that Facebook response was surely typical – the PM shouldn't be allowed to hide behind an error-prone official when it rebounds on him.
Cameron should apologise for this mistake. But with elections in the offing, don't hold your breath.
Alex Stevenson is the parliamentary editor of Politics.co.uk. He jointly employs a nanny with three other parents
The opinions in politics.co.uk's Comment and Analysis section are those of the author and are no reflection of the views of the website or its owners.