It’s a decade since Ellen Kent started touring opera productions featuring the Chisinau National Opera, and conditions haven’t got easier.

“My petrol costs for this tour have gone up by about £30,000,” she says. “Back in 1997 when I started doing this the visas were free. Then they were £45 per person and now they’ve gone up to £90 – that adds another £30,000.

“Ticket prices haven’t gone up to match and people aren’t coming in any greater numbers. I’ve noticed that some venues are slightly down this year, but we’re still here, still touring on a massive scale.”

And in fact there is a new twist this autumn with the launch of a new company, Ellen Kent and Amphitheatre Productions, which is touring a repertoire of popular operas in a portable amphitheatre setting. It comes to Birmingham for the first time on Sunday, for a one-night-only performance of La Boheme.

The idea came out of a performance of Carmen commissioned for Leeds Castle in August. The flexible amphitheatre, inspired by venues like the Colosseum in Rome and the Arena di Verona, was designed by Will Bowen, one of the founders of the Almeida Theatre.

“It’s probably the most expensive set I’ve had built in my life, but its magnificent,” Ellen Kent enthuses. “It’s on two levels, and has Greek and Roman statues.

“It’s adaptable, so we can we can have a large amphitheatre or a small one. It’s quite light, not massively heavy, which you would think to look at it. It does take a little bit longer to get out than our normal sets, but we’re working on that.

“We’re coming back in the spring with Aida, but you do have to select the operas. If I was doing Butterfly I would not put it in this structure – that wouldn’t work at all.”

* Ellen Kent presents La Boheme, performed by international soloists alongside the Chisinau National Philharmonic Orchestra and Chorus at the Alexandra Theatre on Sunday at 7.30pm (Box office: 0844 847 2294).