Martin Lewis have issued an urgent warning to people who planned to travel over the festive period, but now won't be able to do so.
Millions of people in London and the South East were plunged into Tier 4 on Saturday, meaning many people were forced to change their Christmas plans.
Speaking to those p eople in Tier 4 Chief Medical Officer Chris Whitty said: "My short answer would be ‘please unpack [your bags] at this stage.
"If [people] were to travel with this new variant, unwittingly, to an area that has a low prevalence and starts this being seeded even more outside the high prevalence areas that would be a significant risk to the area they went to.
"That is the reason we are really keen that people do not go from these areas."
Transport Secretary Grant Schapps confirmed that refunds would be available for those who had booked train and coach tickets, but said nothing about flights.
And Money Saving Expert Martin Lewis has warned that people won't necessarily be able to get a refund for flights if they are no longer able to travel - reports the Manchester Evening News.
Posting on Twitter, he said: "Many who can't now travel due to tier 4 asking if due flight refund. If flight cancelled yes. If not sadly no under main EU reg264 & most travel insurance won't cover.
"Though @CMAgovUK says firms should refund but that isn't court tested So if says no to refund, I'd grab voucher/rebook if offered."
A Twitter user then asked if people would automatically be entitled to a refund if they live in Tier 4 areas.
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They said: "Given that Heathrow and Gatwick are in tier 4 and that there is a travel ban they must surely be compelled to cancel flights!!!"
However, Martin explained that the rules aren't about where airports are located, but where people live.
He said: "No the rules is about where people live not airport location. So someone from tier 2 can fly from airport in tier 4."
