(Reuters) - U.S. President Barack Obama on Tuesday vetoed a measure by Republicans in Congress that would have blocked a government labor agency’s rules designed to speed up the time it takes to unionize workers.

U.S. President Barack Obama delivers remarks before signing a disapproval of S. J. Resolution 8, a joint congressional resolution that would block a National Labor Relations Board rule allowing faster union elections, in the Oval Office at the White House in Washington March 31, 2015. REUTERS/Jonathan Ernst

The rules would shorten the period between a union filing a petition to represent workers and an election, from the current median of 38 days to as little as 14 days. Employers would be required to share workers’ names, addresses, phone numbers and email addresses with unions.

The National Labor Relations Board adopted the rules last year and they are set to take effect April 14.

The Senate and House of Representatives, voting along party lines, approved a resolution this month that would have stopped enactment of the rules.

On Tuesday Obama, following through on a threat to reject the resolution, said the rules represented modest changes that would make it easier for workers to unionize.

“Unions historically have been at the forefront of establishing things like the 40-hour work week, the weekend, child labor laws, fair benefits and decent wages,” Obama said at a press conference.

The labor board still faces court challenges in Washington, D.C. and Texas over the new process from business groups who say it violates the National Labor Relations Act by not giving employers enough time to prepare for elections.

Rep. John Kline, a Minnesota Republican and chair of the House Education and the Workforce Committee, said in a statement that the new process would only help unions.

“With his veto, the president has endorsed an ambush election rule that will stifle employer free speech, cripple worker free choice, and jeopardize the privacy of working families,” Kline said.

The NLRB and Democrats who support the rules say they were designed to rein in misconduct by a minority of employers who draw out the union election process in order to threaten and intimidate workers.

An NLRB spokeswoman declined to comment on Obama’s rejection of the resolution.