UK tourists travelling to Europe could face mobile phone roaming charges post-Brexit.
The Guardian reported this week on a leaked document showing how UK citizens could face the additional charges.
Liberal Democrat leader Tim Farron said: "From food and petrol prices to mobile phone bills, it's clear Brexit is hitting consumers in the pocket.
"Families shouldn't pay the price for this government's reckless hard Brexit plans.
"Theresa May must fight to keep hard-won benefits for British consumers in the coming negotiations.
"Most importantly, the British people must get the final say on the government's Brexit deal at the end of this process so they can decide if it's right for them."