Leading article: Londoners must vote for a credible mayor

HOW MANY people vote in today's London referendum on the plan for an elected mayor matters as much as where they put their crosses. No wonder Tony Blair has been drumming up support and Environment Department officials allowing smiley faces on ballot papers to count as a "yes". If the pundits are right and polling stations see participation at usual local government levels - 40 per cent or less - it will be hard to claim full endorsement for the plan. The Government says the referendum is only advisory - it will proceed regardless of the size of the vote. But how hollow the thing will look if Londoners stay away. Any future claim to legitimacy by a mayor - especially in his or her inevitable battles with Whitehall over money or powers - is going to be vitiated to the extent the electors choose to express indifference today.

The Government's plan for London is far from perfect. It runs the risk of spreading a luxuriant new foliage of office-holders and advisers above the boroughs. At the same time the mayor may be impotent; the Treasury has ensured there is no financial Viagra around. This will be a mayor whose financial discretion is limited to the scrapings of parking charges. Yet the main issue for most Londoners is transport investment and pricing. In principle a determined mayor would be in a position to lobby, to streamline, to plan. In practice the purse strings are going to be tied tight; already a major option - privatisation of the Tube - has been ruled out by John Prescott. Still, the very existence of a figure able to see how policies for parking, buses, trains, housing and employment intersect must be welcome. Those who argue that the existing machinery broadly works miss the fact that it operates in semi-privacy; Londoners are alienated from the authorities operating in their name.

Which makes it all the more necessary for them to turn out and vote. In Scotland, an expression of the "settled will" of Scottish residents was required - no one doubted it was obtained in last year's referendum. The Welsh margin was slimmer and the momentum behind plans for the Principality correspondingly reduced. If Londoners cannot be bothered, it will be very hard to muster the enthusiasm which the actual contest for mayor in two years' time ought to stimulate.