The pulling power of a Hollywood A-list star and the timeless charm of Shakespeare have combined to make Othello, which opened last night at the Donmar Warehouse, the most desirable ticket in town.

The appearance of Ewan McGregor as Iago alongside fellow film actor Chiwetel Ejiofor has created a demand for tickets in the West End usually associated with rock concerts.

Tickets that should cost a maximum of £29 have fetched £800 on the internet auction site eBay but some people are offering them for up to £2,000. The potential for profit is so high that the Donmar has intervened with a warning that any ticket sold on for profit will be invalid.

Staff are monitoring ticket exchanges and have sent written warnings to sellers reminding them of the terms printed on the back of the ticket. Clause 11 states that “tickets may not be resold or transferred for profit” and that “to do so will render tickets void and the holder will be refused entry”.

A spokeswoman for the theatre told The Times that it would be enforcing the policy when it had gathered evidence that a ticket had been resold. “Any ticket that we discover we will make void,” she said. “They will be turned away. We have contacted people who are in possession of the tickets and we hope that they’ve got the decency not to sell them on.”

The high prices have been matched in theatre only by Sir Ian McKellen’s appearance in The Seagull in Los Angeles. A pair of $90 tickets sold for $2,500 (£1,215).

The Donmar sold 23,000 tickets within three hours of their going on sale in mid-October. The only remaining tickets must be bought directly from the box office, where ten seats will be made available at 10.30am every day for that day’s performance. Another 20 standing places for the three-hour play will also be sold.

Box-office staff said that demand had been created by the “Ewan McGregor factor”. The actor, who commands £5 million a film and is best known for his roles in Trainspotting and Star Wars, has already had experience of the buzz he can cause in the West End. People camped outside the box office from 6am when he appeared in Guys and Dolls in 2005.

His film career has left little time for stage work, however. His last stage play was Little Malcolm and His Struggle against the Eunuchs, which transferred from Hampstead Theatre to the West End in 1999.

Ejiofor is thought to be one of the country’s brightest acting talents. He is best known for his film roles, which have included playing a drag queen in Kinky Boots and a heroin dealer in American Gangster. His stage work includes Romeo and Juliet and Peer Gynt, both at the National Theatre, and The Seagull at the Royal Court.

The cast was assembled by Michael Grandage, the Donmar’s artistic director, who is considered by theatregoers to be a guarantor of quality.

Terri Paddock, who runs the theatrical website Whatsonstage, said that the Shakespeare was proving to be the biggest draw at the theatre this Christmas. “It’s amazing, at a time of year when you would expect people to be seeing pantomime, that the three hottest tickets are Othello, King Lear with Sir Ian McKellen, and Much Ado about Nothing at the National Theatre.”

In The Times Magazine on Saturday McGregor said of his preparation for the play: “I've never had to work harder than this. I mean, the sheer size of it. Since being in South Africa in August, I've done almost nothing except work on the play and prepare myself for the part.

“Everyone was saying, ‘Oh, you’re in London, can we have you for this, or this?’, which was nice, but I just had to say, ‘Sorry but no,’ because all I wanted to do was sit at home and learn the script.”

Grandage said that he had been trying to lure McGregor back to the stage ever since he directed him as Sky Masterson in Guys and Dolls.

The McGregor effect

–– Earned £1 million for his role in Star Wars Episode II: Attack of the Clones, which took about $650 million (£316 million) at the box office

–– He recently took a pay cut to appear in Scenes of a Sexual Nature, in which he played a promiscuous gay man, earning £285 for a week of filming

–– He signed a £1 million book deal for Long Way Round, the bestselling account of a motorcycle trip around the world

–– He recently signed a multimillion pound deal to be the face of Davidoff Adventure, a new fragrance for men

–– The sale of his biking outfit and a replica of a motorcycle he used for Long Way Down, another motorcyling trip, this time through Africa, raised £300,000 for Unicef

–– His top-grossing film was Star Wars Episode I: The Phantom Menace, which took $926 million at the box office

–– According to The Sunday Times Rich List, he earned £5 million in 2001 and £8.5 million in 2002

Source: Times database

Explore Stage

• Theatre

• Comedy

• Opera

• Dance

Editor's choice

• Here comes summer: our cultural must-sees
• Friends reunited: Sex and the City
• New country for old men