THE Competition Commission is preparing proposals for Britain's key airports that are likely to lead to a near-dismantling of BAA and have far reaching consequences.

Aside from the arguments over the core issue – whether BAA's monopoly stifles competition and efficiency – the timing of the announcement, due on Wednesday, could also play into the hands of the company's detractors.

Thousands of holidaymakers are pouring through airports that continue to suffer delays and over-crowding, adding to public dissatisfaction and calls for BAA's bosses to be hung out to dry.

This is despite the millions spent on easing the congestion. And therein lies a problem for the commission. BAA has invested heavily in baggage checks, increased staffing and new terminal facilities. Queues are still with us, but are shorter and faster moving. Should the company be ordered to sell one, two or more of its airports, would a new owner find a magic wand that would make all the remaining problems disappear?

As highlighted in our analysis on page 5, BAA's case has been wounded, possibly fatally, by the fiasco surrounding the opening of Heathrow's Terminal 5, although British Airways must share the blame for making the move before it was ready to do so. Amid the chaos, nobody emerged smelling of roses. There were some sudden departures – among staff, rather than aircraft – and the case for forcing BAA to offload some of its seven airports looked indisputable.

Another growing irritation is the way in which terminals have been turned into shopping malls. The option of spending money on unnecessary gadgets and yet more fashion items may relieve the boredom for passengers awaiting delayed flights, but tackling the flight delays at source would be preferable.

The weight of public opinion now seems heavily balanced against BAA retaining its current status, although there is a danger that in the clamour for a break-up, a lot of the evidence against such a move will be ignored.

Commentators in the south continue to question BAA's ongoing ownership of both Glasgow and Edinburgh, due to "proximity", yet as our analysis reveals, the two airports serve distinct markets, so much so that a number of carriers operate out of each city to the same destinations. If there was overlap, the carriers would settle for one or other airport.

And while competition may lessen the need for price caps on landing charges, the evidence of over-charging is hardly overwhelming. The two biggest Scottish airports voluntarily keep charges at 3% below the retail price index and charges are in the bottom quarter when compared with rival European airports.

What of the London airports? Our sources tell us that Gatwick is the more likely candidate for sale, largely because the Government wants to see an extra runway at Stansted and Heathrow and its plans would be in disarray if either of these were to be put on the block.

BAA's argument, a view echoed in this column, is that the real issue is capacity, not competition. You only have to witness the congestion and delayed flights at London City Airport to realise that the BAA-owned facilities do not have a monopoly on chaos. So much for competition.

There have been recommendations in recently published studies that City should host more of the short-haul flights, including business flights, relieving pressure on Heathrow. But surely that means more cooperation between airports, not more competition.

A growing number of Heathrow's clients have already moved flights to the east London hub, which is seeing a 20% rise in passengers each year and is popular for its easy access to the City and Canary Wharf.

Luxair moved its entire operation from Heathrow to London City, Air France bought Belgian business airline VLM to gain a stronger foothold in the airport and Swiss is increasing flights to Zurich.

The "Heathrow refugees", as City boss Richard Gooding describes those making the switch, are helping to ease the problem at bigger airport that is fundamental to improving its performance, particularly as fierce local opposition is casting serious doubt over it ever getting a third runway.

Reducing passenger numbers at Heathrow or increasing the capacity for more flights is the only way to improve it.

But a new owner would be unlikely to volunteer a cut in customers and will have the same issues over getting a new runway.