The Daily Telegraph's Charles Spencer, the Mail on Sunday's Georgina Brown and The Observer's Susannah Clapp have all departed. Matt Wolf, who writes about London theatre for the International New York Times, and Libby Purves, formerly chief critic of The Times and now of her own theatre blog, Theatrecat.com, remain on the panel, as does the Evening Standard's theatre critic Henry Hitchings and the paper's editor Sarah Sands.

In a feature for The Daily Telegraph, Charles Spencer explained his reasons for leaving: "There is no way of knowing for sure, of course, as the winners emerged from a secret ballot, but my impression from the discussions was that the strongest support for best actress was for Linda Bassett for her beautiful and very funny performance in Arnold Wesker’s Roots at the Donmar and Lesley Manville for her superb and harrowing portrayal of Mrs Alving in Ibsen’s Ghosts at the Almeida. But the award went to the starrier Helen Mirren for her performance as The Queen in The Audience who in my memory figured but briefly in our discussions. I have no way of knowing whether she received support from other judges, as the voting was secret. But my jaw dropped when Mirren received the prize, fine though her performance was. The suspicion must be that Mirren, a major star, was felt by the Standard to be a sexier winner with a greater appeal to the paper’s readership than the other leading contenders."

In a blog posting on The Observer's sister site The Guardian, Susannah Clapp concurred: "One of the hard things about the not-very-hard life of a judge is having to put up with not getting your own way. If I had found myself confronted with a wall of acclaim for Mirren from my fellow panellists I would have argued, but conceded the point: she is a good actor; she created a sparky evening. But that was not the case. The names that were mentioned were Lesley Manville, Linda Bassett, Kristin Scott Thomas, Lia Williams and Billie Piper. Because the ballot was secret, I have of course no way of knowing whether everyone else voted against the tendency of their speech. (I doubt it.) And I still don't fully understand what happened. We asked what would occur if a particular award was disputed or difficult. We were told we would be consulted. We were not."

According to a news feature in The Times, there had been a dead heat between two of the other nominees, and rather than give the award to both actresses – as happened when Adrian Lester and Rory Kinnear tied for the Best Actor category for their performances in the National Theatre's Othello – the paper's theatre critic Henry Hitchings changed his vote, enabling Mirren to overtake both of them.

Sarah Sands told The Times, "In discussion about what was a dead heat, Henry and I decided that we would go for an option that would make Helen Mirren the winner. By doing a first and second vote we could balance the two factions with a third option, which is what happened. It was an absolutely legitimate choice… It would be absolutely wrong to suggest that there was anything untoward about the process."