Which party will oppose Harper's anti-trust anti-trust tax?

See also: Harper's anti-trust tax was an anti-trust tactic

Competition law, known in the United States as antitrust law, has three main elements:

* prohibiting agreements or practices that restrict free trading and competition between business entities. This includes in particular the repression of cartels.

* banning abusive behaviour by a firm dominating a market, or anti-competitive practices that tend to lead to such a dominant position. Practices controlled in this way may include predatory pricing, tying, price gouging, refusal to deal, and many others.

* supervising the mergers and acquisitions of large corporations, including some joint ventures. Transactions that are considered to threaten the competitive process can be prohibited altogether, or approved subject to "remedies" such as an obligation to divest part of the merged business or to offer licences or access to facilities to enable other businesses to continue competing.

The substance and practice of competition law varies from jurisdiction to jurisdiction. Protecting the interests of consumers (consumer welfare) and ensuring that entrepreneurs have an opportunity to compete in the market economy are often treated as important objectives.

Competition law is closely connected with law on deregulation of access to markets, state aids and subsidies, the privatisation of state owned assets and the establishment of independent sector regulators.

In recent decades, competition law has been viewed as a way to provide better public services. Robert Bork has found that competition laws can produce adverse effects when they reduce competition by protecting inefficient competitors and when costs of legal intervention are greater then benefits for the consumers. The history of competition law reaches back to the Roman Empire.

The business practices of market traders, guilds and governments have always been subject to scrutiny, and sometimes severe sanctions. Since the twentieth century, competition law has become global.

The two largest and most influential systems of competition regulation are United States antitrust law and European Community competition law. National and regional competition authorities across the world have formed international support and enforcement networks.