"If we had disruption for four weeks, would you be able to feed your family?"

The woman posing the question is a "Brexit prepper," somebody who has crammed their cupboards full of groceries, toiletries and household goods just in case U.K. shops run empty at the end of March. The U.K. is set to leave the European Union on March 29.

Jo Elgarf doesn't wait for an answer, explaining that her Facebook group, "48% Preppers" is made up of people who want to publicize that a "no deal" Brexit could mean disruption to the supply chain.

"We had hoped that none of this would be needed but the more they argue in Parliament, the more they forget about us. They've told us nothing about to expect if we go out under no deal," she told CNBC last week.

The 43-year-old Londoner works as an administrator on the Facebook group and is a mother to a disabled daughter. Elgarf believes British people have become too complacent about their food supply, always expecting that items they want will be conveniently available.

"If you are in Canada you go into winter knowing that you've got enough food in case you are snowed in for the month," she said.

"We are so complacent here, we think things are just going to be in the supermarket. So, we're going back to 1970s style that means you want to do your shopping further apart."

After weeks of carrying out U.K. media interviews and with Brexit now less than two weeks away, Elgarf says the time to get her message across has now passed.