Dozens of US Congress members have urged president George Bush to end duties on softwood lumber imports from Canada.

More than 45 congress members signed the letter, which tells the president that duties are harming US consumers and pricing first-time house buyers out of the market.

The letter urges the US government to honour its commitment under the North American Free Trade Association’s dispute resolution process and return the nearly C$4m in duties already collected to Canada.

It says: “The current duties, which have been found illegal under both the World Trade Organisation and NAFTA, deprive Americans of affordable housing, the first step in the American Dream.”

American Consumers for Affordable Homes applauded the politicians’ initiative and accused US special interests of destabilising the lumber market for their own gain.