"tough labor" is a grammatically correct phrase and is commonly used in written English.
It is typically used to describe difficult or physically demanding work. Example: The construction workers endured tough labor as they toiled under the scorching sun to build the skyscraper.
Caterpillar has a long history of tough labor negotiations and bitter labor disputes.
"But he has proven over the years to be a very tough labor negotiator.
He earned his man-of-the-people reputation as a tough labor negotiator, a maker of deals, not of speeches.
Union officials say this push caught them unaware when it helped elect conservative lawmakers throughout the country in 2010, many of whom then pursued tough labor legislation.
He faces a budget deficit of up to $2 billion next year, and tough labor negotiations with the city's municipal unions.
Northwest Airlines and its mechanics have reached a tentative deal, but tough labor negotiations are still in progress at Delta, United and American.
Those with jobs are seeing tougher labor conditions as companies struggle to compete with low-wage international rivals.
Recent graduates, for example, have had to begin their careers in the toughest labor market since the Great Depression.
This is where Heracles finished his toughest labor, dragging the monster dog Cerberus from the kingdom of Hades below.
From further to the left on the political spectrum, there have been calls for tougher labor laws to spur higher wages, more income distribution, and centrally-directed investment.
On virtually every nettlesome trade issue of the Clinton administration, Mr. Gephardt has joined the opposing charge, calling for tougher labor, environmental and human rights standards.
