Endless task to end

[snopes]

The never-ending job of painting the Forth Bridge will be finished within four years, Network Rail said. Work to cover the structure with a special paint developed for oil rigs and expected to last at least 20 years will bring to an end an urban myth. Painting the Forth Bridge became a popular figure of speech for any job that seemed to take for ever. In 1998 it entered the Cambridge International Dictionary of Idioms.

http://www.timesonline.co.uk/tol/new...cle3393275.ece