This week's Car Park Panto performances in the grounds of Knebworth House have been cancelled.
Actors from Horrible Histories were due to perform Horrible Christmas live on stage at three sold-out shows at Knebworth House on Christmas Eve.
However, with Hertfordshire now under Tier 4 restrictions, those drive-in Christmas shows have been called off along with three scheduled performances at Newbury Racecourse on Wednesday, December 23.
Drive-in entertainment is permitted in all other tiers.
A statement posted on the Car Park Party website said: "Unfortunately, due to two of our venues being placed under Tier 4 restrictions, we don't feel it's right to ask our customers to go against the government's guidance to 'stay at home' and so Car Park Panto is unable to go ahead at Newbury Racecourse and Knebworth House this week.
"With help from our fantastic partners, the Car Park Panto elves have been working incredibly hard to bring a little bit of festive cheer to families this Christmas and we are so sad not to be bringing the performance of Horrible Christmas to Newbury and Stevenage."
Ticket holders will be automatically refunded to their original payment method.
The COVID-19 update from organisers added: "Again, we are so sorry that we can't bring Car Park Panto to Newbury Racecourse and Knebworth House."
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