Congressional Democrats pressed President Donald Trump on Monday to intervene with Senate Republicans and demand passage of a bipartisan bill to expand background checks for gun purchases.

House Speaker Nancy Pelosi and Senate Minority Leader Chuck Schumer said Trump’s “urgent, personal intervention is needed to stem the endless massacres of our fellow Americans by gunfire.”

They implored Trump in a letter released Monday to “seize this moment when your leadership and influence over Republicans in Congress on the issue of guns is so critical.” Trump must not “squander” the opportunity for meaningful action on gun violence “by acceding to NRA-backed proposals or other weak ideas that will do nothing to stop the continuing, horrific spread of gun violence,” the Democrats said.

The letter came as Congress returned to the Capitol from a six-week break, with gun violence legislation at the top of the agenda following a spate of mass shootings that killed dozens of people.

A group of U.S. mayors, including some where mass shootings occurred, met with White House officials and individual lawmakers to urge approval of a House-passed bill to expand background checks. The bill, approved in February, would expand background checks to cover private sales such as one that allowed a Texas shooting suspect to purchase his weapon before killing seven people last month.

Senate Majority Leader Mitch McConnell has made it clear that he won’t take action on guns without Trump’s commitment to sign a bill into law.

But Trump has flip-flopped on guns, first suggesting he’d be open to background checks legislation or other measures to try to stem gun violence, only to backtrack after speaking to the National Rifle Association and others in the gun lobby. McConnell, a Kentucky Republican, wants to avoid a politically uncomfortable situation of forcing Republicans to vote on gun-control bills only to have Trump reject them.

Nan Whaley, the mayor of Dayton, Ohio, who has emerged as a leading gun-control advocate following a mass shooting that killed nine people in her city last month, said members of the U.S. Conference of Mayors are focusing on background checks as a first step to stem gun violence. A letter signed by 278 mayors from both parties urged Congress to act on the House-passed bill.

Prevention of gun violence crosses party lines, said Whaley, a Democrat. “We want some Republicans to do the right thing here and (vote for) something that 90% of the American people say makes the most sense” to prevent gun violence, she said.

Bryan Barnett, the mayor of Rochester Hills, Michigan, and president of the mayors’ conference, called the White House meeting helpful and said White House officials “listened intently” to the groups’ concerns. Barnett, a Republican, said background checks are “on the table” as part of a “suite” of solutions the White House is considering.

Background checks have strong support in his Republican-leaning city, Barnett said.

“As I drop my kids off at school in a Republican region and in a line of minivans and SUVs … nine out of 10 of those folks don’t have a problem with background checks,” he said. “It’s not something that curtails their ability to own and operate a gun freely. It’s something they understand that we have to do as Americans because we are part of a greater society.”

Missouri Sen. Roy Blunt, a member of GOP leadership, said Sunday that Trump “needs to step up here and set some guidelines for what he would do.”

Asked Monday when he will release his plan to address gun violence, Trump said: “We’re dealing with Democrats. We’re dealing with Republicans. We’re talking about a lot of different things having to do with, as you call it, gun control.”

At the same time, he said, “we have to protect our Second Amendment very strongly and we will always do that.”

Trump is expected to meet with Republican leaders Tuesday at the White House, and gun violence legislation is likely to come up, according to officials familiar with the plan who were not authorized to speak publicly.

Schumer said at a news conference Monday that Trump and McConnell are the only ones who can move the country forward on gun control.

“Two people in Washington can make sure the background checks bill passes: Donald Trump and Mitch McConnell,” Schumer said, “It is totally up to them. They can’t escape responsibility.”

Passing the background checks bill remains a top priority for Democrats, just as it was before lawmakers left for their six-week recess, Pelosi said.

“We are not taking no for an answer. We are not going away,” she said. “What courage does it take to support legislation that will save lives?”

Pennsylvania Sen. Pat Toomey, a Republican who is working with West Virginia Democratic Sen. Joe Manchin on a bill to expand background checks, said Trump “has a real interest in doing something in this area.” Still, Toomey said, “it’s hard to say how this will turn out.”

Democrats said the clock is ticking. At least 51 Americans were killed in mass shootings in August alone, Pelosi and Schumer said, and many others were killed “in the daily tragedy of gun violence in our communities.”

Rep. Veronica Escobar, D-Texas, said the lack of urgency on gun control is baffling to voters in El Paso, where 22 people were killed in a mass shooting last month. Escobar, who was in El Paso during the August recess, said she heard the same question over and over from residents: “Why haven’t we done something to stop this? Why hasn’t the Senate majority leader felt our pain?”

The background checks bill “is the beginning of what Americans want from their government,” she said.

(AP)