By David Shepardson

WASHINGTON, June 16 (Reuters) - General Motors Chief Executive Mary Barra faced questions from U.S. lawmakers on Wednesday on a workers’ vote at a company plant in Mexico and the company's support for emissions reductions.

Barra met with House of Representatives Speaker Nancy Pelosi and other senior Democrats on Capitol Hill, and touted the company's decision announced earlier in the day to boost spending on electric and autonomous vehicles to $35 billion through 2025.

"We're committed to an all-EV future," Barra said in brief comments to Reuters after the meeting. "We had a lot of conversations about a lot of things that we can do to enable EV adoption."

Until November, GM backed the Trump administration's effort to block California from setting tougher emissions standards than the federal government.

Pelosi had expressed disappointment with GM's support for Republican President Donald Trump's position on the emissions rules, a source briefed on the matter said, and she urged GM to work with California and the Biden administration to reach the strongest possible vehicle emissions standards.

The administration of Democratic President Joe Biden is set to unveil revised vehicle emissions rules in July.

GM said last week it backs emissions reductions outlined in a 2019 deal struck between California and other major automakers, but wants the federal government to endorse changes to speed the adoption of electric vehicles.

Barra also faced questions about a delayed worker vote at a GM plant in Silao, Mexico.

Mexico's Labor Ministry scrapped an initial union-led vote in April, citing "serious irregularities," and later ordered the GM union to hold a new ballot within 30 days of its May 11 statement. No vote has been scheduled

The U.S. Trade Representative's Office in May asked Mexico to review potential labor abuses at the Silao plant under the United States-Mexico-Canada Agreement (USMCA).

Last month, U.S. Representatives Dan Kildee, Bill Pascrell and Earl Blumenauer, all Democrats, pressed GM to answer questions about potential abuses in Mexico.

"We want to see some real demonstration of embracing the labor standards in Mexico -- more than compliance," Kildee told Reuters after the meeting. "The situation in Silao -- I raised that with Mary -- that's a problem."

The Democrats urged GM to commit to providing workers with physical copies of the contract, publicly posting contracts and to meet other requirements.

Kildee offered additional steps GM could take to support workers and meet USMCA requirements, and the three lawmakers followed up with a written list of suggested actions, congressional aides said.