More than a fifth of people do not use their reusable water bottle, or have lost it and not bothered to replace it, a survey has shown.
While the BBC's Blue Planet II and campaigns by various organisations have raised awareness of the problem of plastic waste in the world's oceans, it does not seem to have translated into action, Keep Britain Tidy and Brita said.
Only 36% regularly carry a reusable water bottle with them, and fewer than a third (31%) feel guilty purchasing throwaway bottled water, a survey for the campaign group and company found.
While more than half (55%) said they owned a reusable water bottle, 17% of the 2,138 people questioned by YouGov have one but do not regularly use it and 2% have never used the one they own.
Meanwhile 3% have lost and not bothered to replace their reusable bottle.
A lack of water options at transport hubs is part of the problem, with almost two thirds (63%) saying they buy bottled water when travelling long distances, while 27% are likely to purchase bottled water as part of lunchtime meal deals.
The survey also suggests that the "Blue Planet effect" has not made people feel less awkward about asking for tap water when out and about.
Almost seven in 10 people admitted they felt uncomfortable asking for a free glass of water without buying something else, only slightly down from 71% in 2017, in cafes, shops or other businesses.
And 27% felt awkward getting their bottle refilled even when buying something, the survey found.
The majority of people think there should be greater availability of free tap water across the UK, according to the poll.
Keep Britain Tidy chief executive Allison Ogden-Newton said: "Too many people still find it challenging to fill up on the go, while many more are still embarrassed to ask for tap, worried about the safety of water fountains, or just unwilling to go the extra mile and carry around a reusable bottle.
"We've simply got to get to a situation where topping up in glass or refillable bottle is the norm."
Sarah Taylor, managing director of Brita UK, said that while many people were committed to tackling the problem of plastic pollution, old habits were ingrained and the "hassle factor" often outweighed environmental concerns.
"What's clear is that there is much more we can all do to help people swap for good to things like refillable bottles and reduce their single-use plastic footprint, whether that is reassuring them about the safety of water fountains or making it as easy as possible to fill up and stay hydrated on the go."