Margrethe Vestager has done her sums and found that four into three doesn’t go. The EU anti-trust chief was talking Danish at the time, but the maths is the same in English, and London’s telecoms analysts were almost in tears this week at the prospect of two megadeals falling through.

The one that’s clearly at risk is the takeover of O2 by 3, which would push 3 from fourth to third (of three) in UK mobile. However,  Ms Vestager’s ruling that three operators is too few in Denmark hardly helps that other stirring of Britain’s alphabet soup of operators, BT’s purchase of EE..

The operators all claim that mergers lead to more investment and better service, with the cost savings from economies of scale as a handy by-product. How could we possibly think that cutting the number might lead to less competition?

Unfortunately for the operators’ bluster, the analysts’ reactions rather gave the game away. James Britton at Nomura was quick to abandon his more bullish stance on the sector, arguing that “market repair and consolidation have been compromised”,  while Paul Marsch at Berenberg argued that “this development is likely to undermine investors’ confidence in the sector.”

That confidence flows from the simple belief that a market of three operators means higher prices than a market of four. It must less competitive, as Ms Vestager has noticed. The UK’s domestic equivalent, the Competition and Markets Authority, is considering whether to ask her for authority to rule on O2, and has already called in the BT deal.

Mobile and fixed-line telephony is rapidly converging, and a takeover of EE by BT would recreate something that looks uneasily like the original British Telecom, with all that famous old-fashioned service. EE, itself the product of the anti-competitive merger of Orange and T-Mobile, shocked us with the truth this week.

We EE subscribers already suffer its broadband customer service, but now the company has actually admitted that it’s not quite as good as it should be, even proposing to spend money improving it. Until this actually happens, the thought of adding EE to BT’s monopoly of copper wires, Openreach, is enough to sink the heart of anyone who depends on broadband.

Almost over for Candover

Candover Investments stands as a terrible warning to anyone who thinks private equity is a simple matter of buying a business, piling up debt, and then selling it on. Six years ago, Candover was valued at over £400m. It won a takeover scrap for an oil services group, Expro International, and spread the shares across its PE funds.

It has been a financial disaster. Expro has effectively sunk Candover, with the shares just outside the 90 per cent club. The latest results revealed a 32 per cent fall in net asset value as Expro was written down again. To avoid death by failure to repay debt, Candover has issued 13 per cent pay-in-kind five-year bonds.

Yet all may not be lost. At 212p, the shares are 42 per cent below the last published net asset value, or 20 per cent below JP Morgan’s rather more robust estimate, while an orderly liquidation is releasing cash. The CEO, the appropriately-named Malcolm Fallen, may yet make money on the shares he bought for 228p apiece earlier this month.

When is a plastic bag not a…

Only a fortnight to go before the plastic bag tax causes misery at the checkouts. So what, exactly, is a plastic bag? I’m glad you asked. The Single Use Carrier Bags Charges (England) Order 2015 runs to four parts, 19 paragraphs and seven schedules, drawn to exclude other plastic bags like those containing fairground goldfish (except you can’t do that any more) and bags to carry unwrapped blades (except that you’re taking a chance carrying them at all).

Failure by supermarkets to charge 5p per bag (as defined) risks a penalty notice, opening an exciting new career opportunity as a SUCB inspector. It’s true that the sky hasn’t fallen in other parts of the UK, where carrier bag use has slumped. So instead of re-using them for the rubbish, we’ll be buying rolls of new ones and pretending we’re helping the environment.

This is my FT column from Saturday