WASHINGTON (AP) — President Barack Obama is providing rides to 11 relatives of those killed in the shooting at Connecticut's Sandy Hook Elementary School so they can attend his gun control speech Monday before heading to Washington on Air Force One to personally encourage senators to back gun legislation that faces tough opposition.

After Obama's speech in Hartford, relatives of seven children and one staffer killed during December's massacre at the school will travel back to Washington with him, according to the nonprofit organization that works with the families, Sandy Hook Promise.

The White House says Obama is going to argue in his speech that lawmakers have an obligation to the children killed and other victims of gun violence to act on his proposals.

Gun legislation could come up for debate in the Senate this week as lawmakers return from spring break. The Sandy Hook families want to speak to senators who have not voiced support for the legislation, to ask for support in memory of their children and the school staff who were killed Dec. 14. The White House offered to give the families a ride so they could also attend Obama's speech before their lobbying push.

Sandy Hook Promise said in a statement, "The group is encouraging senators to come together around legislative proposals that will both save lives and respect the Second Amendment rights of law-abiding Americans."

In his speech Monday evening, Obama plans to invoke the memories of the 26 students and staff members killed. He is speaking at the University of Hartford, near the state capitol where last week the governor signed into law some of the nation's strictest gun control laws with the Sandy Hook families standing behind him.

But legislation in Washington faces a tougher challenge, as the nation's memories of the shooting fade with time and the National Rifle Association wages a formidable campaign against Obama's proposals. Senators were negotiating Monday in search of an eleventh-hour deal to expand background checks for gun buyers, after weeks of talks had failed to reach a compromise that could win bipartisan support.

Other measures Obama wants are unlikely to pass. Senate leaders say there are not enough votes for an assault weapons ban. Prospects are also bleak for a proposal to limit the number of rounds of ammunition in a single magazine to 10.

With time running out on negotiations, the White House is making an all-hands-on-deck push this week. Vice President Joe Biden and Attorney General Eric Holder planned to promote their plan at the White House on Tuesday with law enforcement officials. First lady Michelle Obama planned to wade into the debate Wednesday with a speech on youth violence in her hometown of Chicago. And on Thursday, Biden was taking part in a discussion on MSNBC's "Morning Joe" with people who have different views on gun control.

The matter is divisive in Newtown, Conn., as in the rest of the country. Not all Sandy Hook families support gun control, and even those involved with the lobbying push organized by Sandy Hook Promise are not backing the assault weapons ban. But those families are asking lawmakers to expand background checks, increase penalties for gun trafficking and limit the size of magazines. The magazine issue has a particular resonance with those families.

Nicole Hockley told The Associated Press in an interview that she wonders if her 6-year-old son, Dylan, might still be alive if shooter Adam Lanza hadn't be able to bring 10 magazines holding 30 rounds each into the school that day. Lanza was able to get off 154 shots during a four-minute rampage in the school. But he stopped shooting briefly in her son's classroom to reload, giving 11 children time to escape.

"They ran for their lives," Hockley said in a telephone interview Friday. "Dylan was not so fortunate. If there were lower capacity magazine clips, there's a chance Dylan would be here with me today."

Hockley plans to introduce Obama in Hartford and sit on stage during the speech with her husband, Ian. The other families who plan to fly on Air Force One are scheduled to meet privately with the president before he speaks and then attend the speech. Those relatives include:

— Mark and Jackie Barden — parents of 7-year-old Daniel

— Nelba Marquez Greene — mother of 6-year-old Ana

— Neil Heslin — father of 6-year-old Jesse

— Jennifer Hensel — mother of 6-year-old Avielle

— Bill Sherlach — husband of Mary, a 56-year-old school psychologist

— Ben and Cheyanne Wyatt — parents of 6-year-old Allison

— David and Francine Wheeler — parents of 6-year-old Ben