Stonewall, Save the Children, Groundwork UK, Barnardo's and the RSPB are among those that benefit from the right to lobby MPs and Lords directly in the corridors of power.
Pass-holders can enter the Houses of Parliament through the staff entrance, mingle in bars and canteens in both the Commons and the Lords, and enjoy drinks on the Lords Terrace when the house is not sitting.
Some charities have several staff passes: the National Children's Bureau has access for three of its staff, each granted by a different peer, and Lord Rix, president of Mencap, has given passes to three members of the learning disability charity's campaign and parliamentary teams. Lord Victor Adebowale, chief executive of Turning Point, has arranged a pass for the social care charity's public affairs manager.
"It's no surprise to learn that it's who you know rather than what you do that earns charities influence in Parliament," said Adam Rothwell, director of donor advice charity Intelligent Giving, which promotes transparency. "But that doesn't mean we should settle for this imperfect arrangement.
"Parliament should think seriously about how to give fair access to all charities, not just the well-connected. It should award security passes in a fair and transparent way, and every charity should be able to apply for one."
Brian Lamb, executive director of communications at the RNID, agreed that there should be a better system for establishing legitimate access to Parliament.
"It's not clear who's got passes and on what basis," he said. "I don't think it's something to be worried about, but it would be better if there was a simpler and more transparent system - it's a rather arcane set-up."
Ian Leggett, director of People & Planet, said the list indicated that members of the Lords could be more in touch with charities than people assumed. "The second chamber is often seen as being quite isolated, but this list shows an intense focus by a number of peers on the work that charities are doing," he said.
Louis High, head of campaigns and communications at umbrella body the NCVO, said it was crucial for charities to have access to decision-makers so they could "inform, create debate and influence the parliamentary process".