This insistence, that others be allowed to pay tribute to his oeuvre, has to be endured. "I let them get on with it," he cedes, with a smile of resignation. "They would have done it anyway." After the Venice Biennale, there was no turning back. The London vision was in the public domain. So now the painter prowls the unpeopled rooms of the Tate, his framed boards stacked in position against the walls, like replacement windows awaiting an overdue double-glazing operative. He is in the hands of the curators, the facilitators, the talkers-up, the corporate aesthetes. Images, old battles, unseen for 20 years, return to confront him. Willesden Junction, Early Morning, 1962, is given a wary welcome. Paint fresh as a lava stream, bright as molten lead. Surely, after all this time, the thick combings of oil have dried and hardened? The excitement here is of a tightly cropped format suddenly giving way to cinemascope, extending itself into a rushed immensity of landscape, savage implications of light. Multiple railtracks, flying westward, at that point on the North London line where the turn is made, the sweep back towards the Thames and Kew Gardens: a way out. Existence in the city sustained by the fantasy of escape.
It's a very different story for the Whitechapel writers of the diaspora into Hackney, Hendon, Golders Green, the ones who laid down the post-war fables of a hard-lived life: the memory men. There are no retrospective tributes to Emanuel Litvinoff, Alexander Baron or Bernard Kops. Second- and third-hand copies of their books circulate like relics among a small circle of initiates. Occasionally one of them is puffed in the broadsheets and rapidly reforgotten. Art, the image in the investor's frame, carries a different weight, a bulkier price-tag. Aesthetics give way to brokerage. The metropolitan painter signs his Faustian contract for a life of privileged drudgery.
How could it be possible, in a couple of slow circuits of these eight rooms, to evaluate the discoveries, triumphs and uncertainties of a career of such grandiloquent modesty? It's a nonsense to attempt it. Kossoff's works are monumental Polaroids of memory: hundreds of rapid sketches, early or late, at some building site, significant hole in the ground, laying down the prompts for the epic instant of the oil. The paintings are inevitably made on board not canvas, heaped, modelled, moulded, scratched off, begun again. But the labour is to hit that now, the shift out of mundane into transcendent reality. The whole process is rehearsed vision. Compulsive preparation for the revelation that may or may not come, for the seizure of that revelation.
Kossoff denies a master plan, a grand scheme. The city is not to be unpacked, catalogued, revealed. He follows his instincts. A stroll in the sunshine, a tribute to the city's "strange ever-changing light"; light which, in these paintings, seems to have passed, or been squeezed, through the filter of consciousness.
Navigating the rooms where the exhibition is to be held, Kossoff is intent on demystification. He outlines a non-predatory voyeurism, studios in which he has worked, favoured locations: the old room, near Dalston Lane, which overlooked, on one side, the German Hospital, and on the other, the frenzy of Ridley Road market and the salmon curing yard. And always the beloved railway, glinting like a ladder of dreams. Questioned more closely about details, small gestures or marks in the painting, Kossoff will always demur, find a practical solution. Such a thing was happening at such a time, such a man walked past. The trellis of ectoplasm, white vine-threads, that curtain off the immediacy of the image, is no symbolic device. A heavily loaded brush dripped. An acceptable accident. There is, perhaps, something disingenuous here, the effect known and exploited in the long trance of composition. The magician turning aside impertinent enquiry, aligning himself, as visionary artisan, with the lost traditions of East London craftsmanship - the bakers, tailors, builders, draymen and slaughtermen.
The process whereby aspects of the city are reconstructed in the studio, sketches transmuted into large oils, offers itself, against a climate of instant effects and production-line technology, as both documentary and elegiac. The results, according to your standpoint, are heroic or faintly absurd. Lined up for inspection along the gallery walls, the topography of remembrance effects an extraordinary procession: the personal subsumed into the spirit and consciousness of the city. These are no longer Kossoff's own memory shards, he has abdicated all that froth of sentiment, but massive retrievals of place and climate, bulwark architecture around which the clouds break. It doesn't matter that the imagery, to the swift uncaring glance, is alarmingly close to pavement art, or the stuff that used to be rounded up for open exhibitions in the Whitechapel Gallery. Kossoff's swimming pool in Willesden, its seething, gesturing bodies against a blue that surpasses the chemistry of the real, is no faux-naif gesture. It is where he taught his children to swim. It is Willesden on an autumn afternoon in 1971. But it is also a site of ritual, both purifying and Dionysian. Human and trapped in a timeless frieze. The oils, seen together, are like great windows of "slow glass" that cause light to flow more hesitantly towards the eye of the viewer. Time as loaded as the layerings of paint. Trains have slithered to a halt. Pedestrians are stamped down like holocaust shadows. The raw red of a school building seen from the car becomes the brickwork of the tenements around Arnold Circus in Shoreditch, where Kossoff lived as a child. Strange territory with its own microclimate, where time is still in suspension.
It's our business if we want to read more into these works. Kossoff denies that the bare, seven-branched tree that rears above Embankment Station makes any allusion to the Menorah, or ritual candelabrum. The marks on the soft pillars of Christ Church, Spitalfields are not, so Kossoff briskly informed me, cabbalistic, but "a man with a trombone".
Kossoff should be seen as the laureate of the North London line, the poet of embankments and cuttings. The man who, more than anyone else, through his intensely worked panels, celebrates that which will vanish and fade. His paintings are prophetic in their concentration: the perspective of empty tracks speeding into the distance is now made actual through privatisation and the "renovations" that have left the journey from Dalston / Kingsland to Kew as mythical as an expedition to the headwaters of the Amazon.
n The Leon Kossoff exhibition is at the Tate Gallery, London SW1 (0171- 887 8000) from Thurs to 1 Sept. Iain Sinclair's lecture 'The Lambeth Alchemists: Elias Ashmole, Jeffrey Archer and the Golden Griffin' is at the Tate Gallery tomorrow, 6.30pm