MEXICO CITY, April 29 (Reuters) - Mexico's Senate approved a bill to strengthen the rights of trade unions on Monday, one of the final steps towards enacting a law that Democratic U.S. lawmakers have insisted must pass before they can proceed to a vote on the revamped North American trade pact.
The bill, which was passed by the lower house earlier in April, enshrines the right of Mexican workers to organize and gives them more control over their contracts.
House Speaker Nancy Pelosi, a Democrat, had called on Mexico to enact the legislation, saying U.S. Congress could not even begin to take up the pact unless Mexico put the new law in place.
Democratic lawmakers say the new United States-Mexico-Canada Agreement (USMCA) must ensure workers in Mexico have the right to unionize, a step that requires new labor laws.
They argue a major weakness of the 25-year-old North American Free Trade Agreement, which USMCA would replace, is that it allowed Mexican wages to stagnate.
The legislation now heads to Lopez Obrador, who has previously voiced his support for the measure, for his signature.