For the millions of people arriving at Heathrow, Gatwick or Stansted, the break-up of BAA, the monopoly owner, could not come a moment too soon. The litany of complaints, especially about Heathrow, has made BAA one of the world's most reviled airport authorities. The delays, disruption, overcrowding, intrusive security, commercial clutter and poor communications are not all the fault of the airports' owner. But, as the Competition Commission noted in its trenchant criticisms yesterday, BAA has failed to respond to passenger needs, has not taken the initiative in planning capacity and often has subordinated the needs of one airport to its plans elsewhere. As the commission concluded, it is high time this monopoly was broken up.

The results of BAA's unwieldy management are most pernicious in the South East, overwhelmingly the gateway to Britain. Heathrow is not only one of the world's largest hubs; it is vital to Britain's economy and London's attractiveness as a global business centre. Despite the opening of Terminal 5 - which is, at last, proving to be a magnificent hub - Heathrow needs immediate and massive further investment, in both capacity and infrastructure. So too, though on a lesser scale, do Gatwick and Stansted.

The objection to a single owner for all three is not that Ferrovial, BAA's owner, is Spanish (though that chauvinist charge has been voiced too often); it is that the company is so laden with debt that it cannot raise the necessary capital. And proposals to concentrate on Heathrow invariably anger the airlines using Stansted, which complain that they are having to subsidise their rivals' base through high charges.

BAA argues that separate ownership will do little to improve facilities as there is no real competition between the airports. At one level, that is true: airlines cannot move easily to a more attractive base because of flightpaths and because slots change hands for a very high premium. But the competition of example can be powerful. If Gatwick were run much better than Heathrow, passengers would flock to airlines using Gatwick, and the pressure to improve Heathrow would be intense. A similar situation developed in Moscow, when one former domestic airport was rebuilt to a much higher standard and foreign airlines soon moved from the inefficient and poorly run old international airport at Sheremetyevo.

Yesterday's report also addresses two crucial issues constricting Britain's airports: capacity and regulation. Neither is strictly within its remit, and the commission has raised government hackles by urging it to review the 2003 White Paper that laid out proposals for a second runway at Stansted in the next five years and a third short runway for Heathrow by 2015. Ruth Kelly, the Transport Secretary, insisted yesterday that she would still make a final announcement this autumn. Despite protests, the proposals must go through. BAA's objection that break-up would complicate runway expansion is irrelevant.

Regulation is a separate issue. The Civil Aviation Authority has too often proved ineffective, especially in failing to champion the passengers. It needs, for example, to be much firmer in insisting that operators run ports rather than shopping centres, and give priority to the needs of check-in, security and passport control. BAA should have got this balance right but has not.

There will be no shortage of bidders for either Gatwick or Stansted, or other BAA airports that the Competition Commission says must be sold - especially Edinburgh or Glasgow. Proven reserves and expertise are obvious requirements, but the market should itself winnow out the new owners. What matters is that a monopoly not in the interests of passengers, airlines or the British economy should be brought to an end.