But will blue-chips suddenly rush to the new Grant Thornton for audit services? I doubt it, though that may well come in a trickle rather than a flood in time.

It will, however, have caused a few BDO Stoy Hayward partners to choke on their cornflakes on reading the news in yesterday's Sunday Telegraph and Sunday Times. I presume Cleary will have let Jeremy Newman, his counterpart at BDO, know the results of the partners' vote; the two have presented something of a united front in the battle against Big Four dominance. All eyes will be on Newman's blog in the coming days for signs of his reaction. Certainly, though, it is a blow to his ambitions as it puts increased distance between the two firms. BDO's fees for 2006 were £275m – GT's, including Robson Rhodes, would have been £360m.

On the basis that to make a material difference to your revenues you have to merger with a top 16 firm (these are the ones generating fees in excess of £50m), who might BDO be eyeing?

Well, fees per partner at Smith & Williamson and Tenon are comparatively low, though the latter is listed and the former could soon be, which would complicate arrangements. However the really vulnerable firms look to be PKF, which grew by only 3% last year, though its fees per partner are pretty healthy. And Moore Stephens which grew by just 7.3% and is generating just £535,928 per partner. That can't be generating profits that, with all the risks attached, are worth getting out of bed for.

It's going to be an interesting summer.

igAt least he saved us from having to insert our own joke there - though being the financial sophisticates that we are at Accountancy Age our punchline would have involved a devastatingly humorous reference to his questionable reform of ACT a decade ago.

In the interests of transparency I'll declare highlights of the results of a quick straw poll of our writing team: two hold maths A levels - one A (very good), one E (very dim); one abandoned double maths A level after a fortnight; and one failed maths O level.

So I won't hear a bad word said against Brown's shaky grasp of the numbers. Especially as on meeting him at a Downing Street reception last week, he told me Accountancy Age was 'one of my favourite journals'.

I look forward to a slew of comments linking the two.

For while the senior partners of all the firms involved made the usual noises – 'a significant step forward in our growth strategy' in the case of the former, the bringing together of 'talents' and provision of 'synergy' in the latter – there is a wider issue at play.

Most firms right now are afraid that the ladder is about to pulled up from above them. That's why BDO and Grant Thornton are making so many noises about competition at the top end. And it's why firms in the tier below them are talking to each other, mulling mergers and considering collaboration more than perhaps they have done in the recent past.

On Accountancy Age TV this week, Moores Rowland's Fiona Hotston Moore acknowledges that she realised 18 months ago the firm needed to grow through merger to twice its then size to continuing holding its own in its chosen market. (It might explain the firm's curious and longstanding reluctance to supply figures for the Accountancy Age Top 50 too).

The aldder analogy holds true for the rest of the Top 50 – and among the firms below that level too.

So will it be a summer of love-ins; declarations of mutual admiration, aligned strategies and talk of one and one making three? Probably not – but don't expect Mazars and Moores Rowland, Alfred T. Scott and Sinclair Maclean to be the last tie-ups.

Expect that to change in 2008, though, as the pace of reform steps up.

In a week that marks the sixth anniversary of the awarding of the first LLP certificates (18 were issued on that day back in 2001), it all seemed terribly timely.

However, it seems we only knew the half of it.

Last Saturday partners at legal giant Linklaters rubber-stamped a move to convert to an LLP from 1 May, 2007. But that's as nothing compared to the bombshell news from Australia (covered by our sister title Legal Week) that investor and workers’ rights law firm Slater & Gordon is set to become the first law firm in the world to float on a public market.

In doing so the firm is taking advantage of Australia’s recent legislative changes to raise money and open itself to non-lawyer investors – and making a move that's bound to have massive repercussions for professional services firms around the world.

It's hard to imagine that the current accountancy ownership structures (which basically run to two options for audit firms– partnership or LLP) will prevail. We may not see substantial in the next 12 months but, with liability and competition debates still unresolved, change feels inevitable at some stage.