Cagliari, September 6 - A worker from the Alcoa aluminum plant at Portovesme on the Italian island of Sardinia who climbed to the top of a 70-metre silo on Tuesday has fallen ill and may have to be removed, doctors said on Thursday. The man, who suffers from a heart condition, climbed the silo with two other workers in protest over plans by the American aluminium giant to shut down the smelter and put hundreds of jobs at risk. Doctors who climbed the silo Thursday morning are evaluating whether or not the man can be transported down the tower safely. The protest came as a delegation of workers and union representatives met with the leaders of the three parties supporting the government of Premier Mario Monti in Rome to discuss the dispute on Tuesday. It also anticipated a series of initiatives in Sardinia leading up to a demonstration in Rome on September 10 involving hundreds of Alcoa workers, local administrators, trade unionists and ordinary citizens. On Monday Italy's economic development ministry announced that hotly disputed work to begin shutting down parts of the Alcoa plant had been halted pending the outcome of a possible takeover deal with Swiss multinational Glencore. Alcoa has promised to keep all workers at its Portovesme plant employed through the end of the year.