Gun control supporters have won the first Senate showdown over restricting firearms, rejecting an effort by conservatives to derail a package of gun curbs before debate could even begin.

Erica Lafferty (2nd-L) and Jillian Soto (2nd-R), who both lost family members in the Newtown shooting, urge Congress to pass tougher gun laws during a news conference (Mark Wilson/Getty Images)

The 68-31 vote gave an initial burst of momentum to efforts by President Barack Obama and lawmakers, mostly Democrats, to impose gun restrictions following the December carnage at an elementary school in Newtown, Conn.

Gun control supporters needed 60 votes to block the conservatives.

The legislation would subject more firearms buyers to federal background checks, strengthen laws against illicit gun trafficking and increase school safety aid. Advocates say the measures would make it harder for criminals and the mentally ill to get weapons.

Opponents say the restrictions would violate the Constitution's right to bear arms and would be ignored by criminals.

White House welcomes Senate vote on gun control

White House Press Secretary Jay Carney (Chip Somodevilla/Getty Images)

The White House says families of the Newtown school shooting victims may have been "decisive" in a Senate vote on gun control.

The families have been lobbying on Capitol Hill ahead of Thursday's vote.

Senators blocked a conservative effort to prevent debate on a package of gun measures.

The White House is welcoming the vote. But spokesman Jay Carney says that while it is "very important," it is just the "first stage" in the effort to pass anti-gun violence legislation.

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