Theatres suffered a string of cancellations across the Christmas period, with The Lion King and Life Of Pi among the shows that had to dim their lights due to Covid-enforced staff shortages.
Mary Poppins at the Prince Edward Theatre will now move from eight to six performances a week for a month from Monday.
A message from Delfont Mackintosh Theatres, which operates the venue, noted the “significant impact the Omicron variant and the Government’s move to Plan B” has had on the West End in the past month.
It added: “The producers of Mary Poppins therefore had to consider carefully how best to react to the situation.
“They have had to take the very difficult decision to temporarily reduce the number of shows in the schedule to 6 shows per week, cancelling the Monday evening and Thursday matinee performances from Monday 10th January to Thursday 10th February inclusive.”
The Phantom Of The Opera at Her Majesty’s Theatre also scrapped two performances a week.
An email sent to patrons said: “Unfortunately, the uncertainty surrounding the ongoing pandemic is likely to continue for some time as we head into the new year.”
The theatre said Monday evening performances from January 10 to January 31, inclusive, and Thursday matinee performances from January 13 to February 10, inclusive, would be cancelled.
It comes after the West End suffered a raft of postponements and cancellations during the lucrative Christmas period, as the Omicron variant prompted a rise in case numbers.
On December 21, Lord Andrew Lloyd Webber cancelled his theatre production of Cinderella until February “to avoid more disruption”.
He added: “Once again, this wretched virus has put paid to the joy of entertaining audiences, something that I hold so dear.”
Performances of Cabaret At The Kit Kat Club, featuring Oscar-winner Eddie Redmayne and Jessie Buckley, at the Playhouse Theatre and the National Theatre production of Hex, based on the classic fairy tale Sleeping Beauty, were also scrapped.