Raben Group is working for Islamic Relief Worldwide, the UK-based Muslim charity, to educate Washington about its programming.
Israel has banned IRW, accusing it of funneling cash to Hamas, charges rejected by the organization.
Founded in Birmingham 30 years ago, IRW operates in more than 40 countries including Pakistan, Albania, Syria, Afghanistan, Ethiopia, Lebanon, Indonesia, Gaza/West Bank, China, India and Bosnia.
The UK government's international development arm budgeted about $4M for IRW in 2014.
Robert Raben, counsel to former Massachusetts Democratic Congressman Barney Frank and assistant attorney general, spearheads his firm's IRW work.
Karen Marangi, one-time aide to Sen. Pat Leahy (D-VT) and his former colleague Alan Cranston (D-CA); Joe Onek (senior counsel to ex-House Speaker Nancy Pelosi), and Alexandria Walden (Center for American Progress alum) assist Raben.