The creators of the acclaimed theatre show You Me Bum Bum Train provoked acrimony among its army of unpaid volunteers after staging a performance for the Amazon founder Jeff Bezos.

Performers in the immersive production were “horrified” after being thrust in front of the world’s second-richest person and his partner Lauren Sánchez with just seconds’ notice.

The pop-up London show, which has received rave reviews and whose £100 tickets sell out in minutes, relies on thousands of volunteers to bring its surreal worlds to life. Yet disquiet has grown among a cohort of volunteers about some of the famous people able to access the guest list by buying “patron” tickets or booking private nights.

Although long beloved by celebrities such as Stephen Fry and Madonna, it is the presence of high-paying figures from the worlds of finance and politics that has attracted unease. Those concerns were recently outlined in a letter to the show’s creators, Kate Bond and Morgan Lloyd, by three volunteers addressing the presence of “potentially contentious individuals”.

The letter began circulating in the theatre world last week, adding to the show’s mystique, which is maintained by an insistence on guests and staff signing non-disclosure agreements.

Tensions among some volunteers flared when Bezos and his partner attended the production on March 28 along with an entourage including some of the American billionaire’s family. A volunteer said that both they and colleagues were left “incredibly upset” after feeling obliged to perform for Bezos.

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As well as unease at the unpaid work for one of the wealthiest living people, they expressed outrage at “being put in a room with someone who is working to support the destabilisation of US democracy”.

Unlike traditional theatre settings, the production involves performers and theatregoers — of which only one takes part at once and 77 over the course of a night — being placed in often intimate settings.

The volunteer said that performers were given little more than a minute’s notice that Bezos was a guest. Names of those with tickets, known as “passengers”, are read out at short notice so that performers can opt out if they know the person. Both performers and guests can also call a “time out” and stop the production at any stage.

The volunteer said that they were given so little time to consider performing for Bezos that they felt there was little choice but to partake.

They added that two volunteers were “visibly unhappy” at Bezos’s presence, although others were nonplussed, treating him as they would any other celebrity guest.

“I wholly support the making of bold and daring art, and I’m really glad that YMBBT has given so many passengers and volunteers a ‘life-changing experience’,” the volunteer said. “But the organisers owe us some respect and a sense of safety, and they let us down here.”

Four days after the performance, Bond and Lloyd emailed volunteers who performed that evening to address the production’s “approach to keeping the experience open to everyone — even when it features high-profile figures”.

The message said: “Bum Bum Train is built on empathy. We’ve seen how experiencing the show can affect meaningful change, even in the most unlikely passengers.”

Other in attendance who have raised eyebrows include Joshua Kushner, the American billionaire venture capitalist whose brother Jared is President Trump’s son-in-law.

The show’s reliance on volunteers has long been a source of controversy, with the actors’ union Equity opposed to the practice.

However, Bond and Lloyd have espoused the benefits of volunteering and many who have taken part have hailed their experience. Rather than a commercial endeavour, the production is described as a not-for-profit community theatre project.

The creators, who first staged the show in 2004, have only recently started taking a wage from the company, alongside about 20 production staff. They have also been open about how selling higher-priced tickets to private buyers offsets the cost of public tickets, which they estimate would cost £6,000 each without the use of volunteers.

The production company said that only a tiny fraction of its volunteer base had raised concerns and that the letter was penned by a recently joined volunteer unfamiliar with its processes.

A source said that the show creators believe it should be open to all, a position that is justified if there is “even a small chance that someone in power walks away from Bum Bum Train feeling more empathy, more connection, and more responsibility”.

They added that there was already an internal procedure in place for volunteers to report if they feel uncomfortable and unsafe. The production team has accepted this should be more visible after speaking to the letter writer.

A spokesman said: “You Me Bum Bum Train never discloses information about its passengers. The production receives no Arts Council or private funding. It is made possible through ticket sales alone, a portion of which are allocated as private nights and patron tickets in order to offset the cost of the public tickets — a fact YMBBT openly communicates to the public, press and any volunteers who choose to donate their time to making the show happen.

“Additionally, YMBBT remains transparent about how any passenger donations are used, as and when they are received.”