Boris Johnson has said the government "can’t rule out" tougher measures on cross-Channel travel.
Speaking to MPs, the prime minister said: "I think we now, in all seriousness, need to look at the situation at the Channel. I’m afraid we can’t rule out tougher measures and we will put them in if necessary."
It comes as Europe faces a third wave of the coronavirus.
The prime minister was being questioned by the House of Commons Liaison Committee.
Responding to Labour MP Yvette Cooper, Mr Johnson said that there were currently exemptions on travel restriction for the likes of hauliers who enter the UK and then quickly leave.
He said: "We will take a decision, no matter how tough, to interrupt that trade, to interrupt those flows, if we think that it is necessary to protect public health and to stop new variants coming in.
"It may be that we have to do that very soon."