HOW nice to be a Liberal Democrat these days. Your party is mounting a perfectly timed surge in the opinion polls. Your leader is weaving unscathed through the crossfire between the two other parties’ unpopular frontmen. And you are getting lionised by everyone for your brave and positive stance on the big issues.

It is hardly surprising that tonight is shaping up to be another big one for the Lib Dems.

Yesterday I dropped in to gauge this momentum in two London constituencies, one Labour–held, one Tory — the two most winnable seats for the Lib Dems in the capital. In North London, Hornsey & Wood Green, a mixed collection of urban neighbourhoods that tumble down the slopes from Highgate through Muswell Hill and Crouch End.

And, a couple of bumpy commuter train rides away, in southeast London, Orpington, a pleasant greensward of suburbia, the site of one of the great by-election moments in Liberal history.

Pounding the very different streets of Hornsey and Orpington it is immediately clear why it is such a good time for the Lib Dems. Most obviously, being a Liberal Democrat means being able to say different things to different people. The Hornsey seat was held for Labour at the last election with a majority of more than 10,000 by the resolutely Blairite Barbara Roche. Ms Roche has enraged the Left of her party by supporting the Iraq war, top-up university tuition fees and foundation hospitals.

The Lib Dems are hoping to cash in with a campaign aimed squarely at angry Labour voters who think that their party has betrayed its socialist roots.

The constituency is classic modern left-leaning territory. The Tories, who held the seat not much more than a decade ago, are reduced to a rump. Gone too are the traditional working-class, white Labour voters.

In their place are large numbers of ethnic minorities, especially Asians in the Hornsey and Harringay areas, and in the big houses in Highgate and Muswell Hill, the Shiraz-quaffing, well-educated, Blair-loathing professional malcontents of modern Labour folklore.

The Lib Dem candidate, Lynne Featherstone, a member of the London Assembly, has found rich pickings for her anti-Blair message. In a recent campaign newsletter sent to wavering Labour voters there are more references to George W. Bush than there are to Charles Kennedy.

A ragtag army of antiwar B-list celebrities has bolstered her campaign — from Andy Kershaw, the broadcaster, to Lauren Booth, the Prime Minister’s sister-in-law, and, most proudly for Ms Featherstone, if the effusions on her website are a guide, the favourite son of Muswell Hill, the anti-imperialist firebrand Tariq Ali.

Over in Orpington, once part of the great leafy swaths of safe Tory Outer London, you won’t hear much from Tariq Ali in these final hours before polling. Indeed you have not heard anything from him in the course of the campaign. The Liberal Democrat candidate there is waging a classic Liberal battle against a beleaguered Tory incumbent.

Orpington was won by Eric Lubbock for the Liberals in 1962 in one of the most celebrated by-elections in history. The Conservatives won back this part of their natural territory in 1970, but in the past decade they have felt the steady advance of Lib Dems chipping away at their electoral margins.

Chris Maines, who cut the Tory majority to just 262 here in 2001, is the very model of your hardworking, decent, respectable Liberal candidate. He has fought the constituency four times for the Lib Dems, reducing the Tory majority every time.

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