Picketers and supporters listen to Leo Gerard, International President of the United Steelworkers, at the Copper Cliff smelter picket line, Friday July 17, 2009, where a rally was held in support of striking Vale Inco workers in Sudbury, Ont. THE CANADIAN PRESS/ Gino Donato

SUDBURY, Ont. - Striking Vale Inco workers, their supporters, and labour leaders from around the world are rallying Saturday in Sudbury, Ont.

Bob Gallagher, spokesman for United Steelworkers, says the 11 a.m. start time was delayed to allow an overwhelming number of supporters into the building.

Organizers expect about 5,000 attendees and are billing the event as the largest such gathering ever in northern Ontario.

About 3,200 production and maintenance workers at Vale Inco's Sudbury operations have been on strike since July 13.

The two sides have not met at the bargaining table since then and negotiations are at an impasse.

Saturday's rally will include labour leaders from Australia, Germany, Switzerland, Britain, the United States, Mexico and Brazil - where the parent company is based.