People in Wolverhampton are being urged not to meet up with friends and relatives from other households over Christmas.
The four UK nations are expected to issue sterner warnings about the dangers of mixing over the festive period but sources say the rules allowing three households to mix are "unlikely to change".
"It is becoming increasingly evident that this will be an incredibly risky thing to do," he said.
"I'm really sorry to say that we now need to double down and make what will probably seem like the toughest sacrifice of them all.
“For the sake of yourselves and your loved ones, please don't mix with others this Christmas unless it’s absolutely necessary."
The infection rate in Wolverhampton has risen to 276.4 per 100,000 people in the seven days up to 11 December compared to 238.1 for the week before.