Don't get us wrong. There is no newspaper more in favour of controlling the traffic growth that is snarling up Britain's roads than this one. We have deplored the Government's failure to meets its targets on congestion and have demonstrated how pollution from cars is linked to increasing rates of asthma in children.

Don't get us wrong. There is no newspaper more in favour of controlling the traffic growth that is snarling up Britain's roads than this one. We have deplored the Government's failure to meets its targets on congestion and have demonstrated how pollution from cars is linked to increasing rates of asthma in children.

Yet we are sorry to say we cannot support the Mayor of London's congestion charge experiment – the most ambitious the world has seen – which is due to be introduced in just 36 days' time.

Of course, Ken Livingstone is to be applauded (as always) for sticking his head above the parapet. His boldness is in contrast to the cowardly attitude of government ministers who have fiddled noncommittally on the sidelines, hoping for political reasons to sink Ken on an issue they really support.

But this ambitious scheme, to charge all motorists entering central London £5, shows every sign of being hastily cobbled together. Even supposing the (unproven) technology, to photograph the numberplate of every car in the congestion zone, actually works, there are still too many potential flaws. With the deadline approaching, payment methods have not been finalised. As we report on page 10, the Post Office has pulled out and most garages are boycotting the scheme. More importantly, there has been little improvement in London's ramshackle public transport system to cope with the tens of thousands of extra commuters that it will have to absorb. And residents of areas on the fringe of the zone will have to bear the burden of extra traffic.

Above all, the charge appears to be fundamentally unfair, penalising the less well-off and people who work unsocial hours, while there are no extra sanctions against single drivers in large gas-guzzling cars. For it to work, the new charge must have the consent of the people, or it will go the way of the poll tax, defeated by public protest and non-compliance. And that will set back congestion control by decades.