WASHINGTON — House Democrats will unveil 15 proposals for curbing gun violence that resemble President Barack Obama’s plan and will include a call for banning assault weapons, people familiar with the package said Wednesday. The Democrats’ recommendations will also include barring high-capacity magazines carrying more than 10 rounds of ammunition, requiring background checks for all gun sales and prohibiting gun trafficking, all of which Obama proposed last month. The proposals, to be released Thursday by top House Democrats, were described by people who requested anonymity because they were not authorized to discuss the plan publicly. They represent the initial House Democratic response to the horrific Dec. 14 shooting of 20 first-graders and six adults at the Sandy Hook Elementary School in Newtown, Conn. Even so, the Democrats’ proposals are unlikely to go anywhere quickly in the Republican-controlled House. A spokesman for House Speaker John Boehner, R-Ohio, has said the House will wait to see what the Democratic-led Senate does. Obama’s gun control proposals have been opposed by the National Rifle Association, which is a potent lobbying force on Capitol Hill. In addition, some Democrats — including many from rural or conservative areas — have been reluctant to endorse the president’s plan. That hesitation was underscored Wednesday at a private retreat Senate Democrats staged in Annapolis, Md. At that session, Democrats largely embraced expanded background checks on gun sales, but some senators expressed a desire to avoid voting on an assault weapons ban, according to two people who described the closed-door session only on condition of anonymity. The House Democrats’ recommendations were proposed by the 12-member House Democratic Gun Violence Prevention Task Force, led by Rep. Mike Thompson, D-Calif. Two-thirds of its members had to approve an item for it to be included in their plan, meaning there likely will be Democratic dissenters to some of the ideas. Among the task force members was Rep. John Dingell, D-Mich., the House’s longest serving member. Dingell has been a strong ally of the National Rifle Association, though he has clashed with them on some issues in the past. There has been strong public support for expanding background checks beyond the current system, in which the checks only cover sales by federally licensed gun dealers. The checks are aimed at weeding out gun sales to criminals, people with mental health problems and some others.