Speaking to BBC Breakfast earlier, Mr Dowden said the Conservatives would be holding a "normal Christmas gathering of staff that are in London".
"That is completely consistent with the rules, and I would urge people to keep calm and carry on with their plans," he said.
No 10 party row
But he added: "Of course, if the situation changes and rules need to be updated, we will comply with the rules as they stand at that time."
Asked how many staff would be taking part, he replied: "I'm afraid I'll leave the details of it to others."