Dr Sarah Jarvis has issued a warning over attempting to avoid quarantine rules by driving through countries that aren't impacted by the rules.
Earlier today it was confirmed that France would be added to the UK quarantine countries.
However, appearing on Good Morning Britain today, Dr Sarah warned people driving through the affected countries to get to their destination.
Dr Sarah explained: "Just to point out, very briefly, that if you do come back via a country which isn't under the new quarantine rules that doesn't mean that you can avoid quarantine.
"You can't just decide to go via Italy to get back to the UK.
"Because if you come in and you've been in one of those countries in the last 14 days then you will have to stick to lockdown to the end, from the 14 days that you left that country."
Earlier, Dr Sarah Jarvis also warned of the unknown dangers of coronavirus spreading in food factories.
The TV doctor addressed the news that an outbreak of Covid-19 has been found at an M&S factory for sandwiches.
Nearly 300 staff tested positive at the Greencore factory in Northampton, which employs around 2,100 people.
Sean pointed out that it was a risk eating already cooked food like sandwiches, however Dr Sarah also suggested that the public needed to be wary of the packaging itself - not just the food.
Dr Sarah explained: "Theoretically, even if something is cooked, if the packaging is made up - we know, for instance, in New Zealand they think that the latest outbreak have come through packaging rather than people. Yes there is a risk.
"But it does remind us the virus can survive, I think, for 24 hours on cardboard and up to three days on hard metal and hard plastic.
"So we do know that there are risks, we have seen quite a lot of outbreaks in meat processing factories and other various food processing areas.
"Interestingly it's not always been food but in other countries, for instance, it was a shoe plant.
"In the UK it does seem as though there is a link, we think, between the way people travel to work, where they live.
"A lot of people who work in these processing plants will travel to work together, work together and they'll come home together.
"They'll socialise together and often they'll live together and it may be more to do with that."
*Good Morning Britain airs weekdays at 6am on ITV