The portrait is made up of a total of 15 panels, each 5m long and 3m high, and Mach and his team of assistants are only on the fifth and sixth panels, hence his anxiety - "We have to do one panel every 10 days, and there's no slacking. Normally in my work you get the odd day off."
Each panel will feature thousands of images, ranging from snaps submitted by the public, to bits of famous paintings, to adverts cut out of magazines, to the work of commissioned photographers. "The panels will form one seamless landscape, going from town to country and back again," says Mach. "It's a celebration of what we are as a nation as we go into 2000, made up of things from everybody's lives. Not everything in it is rosy, there'll be a few people sleeping in doorways, and there's lots of different things layered into it, which can be quite subversive."
Talking in the organised chaos of his south-east London studio, not far from the Dome itself, Mach compares the job of masterminding of The National Portrait to that of a Hollywood film director. "I can just say, `Right, I want 200 horses coming in here from the left, but I want people on them, and I want them all to be doing something completely different.' The detail is extraordinary. It's fucking big. It's going to be like being machine-gunned with information ... if we get it finished."
David Mach is still seeking contributions from the public. Please send photographs, on any subject (but which should not be posed), to `The National Portrait', Freepost Lon15234, London SE10 0BR. Names, ages and home towns should be written on the back of the photographs, which cannot be returned