IN 1997 the Conservatives handed the poisoned baton of the Millennium Dome to Labour. Will Labour return the favour at the next election by leaving the Conservatives to run the last lap of the Olympic Games relay? Almost two years after London was chosen for 2012, yesterday's statement by Tessa Jowell, the Culture and Sports minister, was hardly reassuring about the progress that has so far been made. Everyone expects the original estimates for holding an Olympics to increase. But by a factor of four?