Although the Labour opposition supported the treaty, they were prepared to tactically oppose certain provisions to weaken the government.

The provision, signed into law in October, weakens two obscure but important bulwarks of liberty.

Mr. Clinton has said he shares some concerns raised by Mr. Bush that this provision would weaken patent protections for biotechnology companies, discouraging research and innovation.

The provision would weaken controls on exporting bomb-grade uranium to plants abroad for use in making medical isotopes - radioactive materials used to diagnose and treat various illnesses.

Democrats say the provisions would weaken Clinton-era protections for national forests.

This provision weakens a substantial benefit of changing the tax treatment of dividends.

"This provision digs the hole even deeper, and weakens important protections that have been built into the system over the last 16 years."

Another provision of the bill would weaken the present system of controlling wiretaps by Federal agents.

The new Cafta agreement was criticized by global health advocates who said that the provision strengthening intellectual property rights would weaken generic drug manufacturers in the region.

Democrats contend that the last provision will weaken unions, and it is the target of their filibuster.