Thousands of people do not have access to basic toilet facilities in their workplace in the UK, according to a major union.

Unite said it had uncovered evidence of staff at branches of big high-street banks being required to urinate in buckets, and construction sites failing to provide any female toilets.

Bus drivers had been denied toilet breaks for up to five hours, and workers in call centres for big financial institutions were told to log in and out to take a toilet break.

In total, Unite said tens of thousands of workers across the UK suffer a lack of “toilet dignity”, where they are either not provided with proper toilets or have restrictions placed upon them in using facilities,

The union said it was demanding that employers take action to ensure that workers had decent toilets without unnecessary or officious restrictions. It said that the worst practices it had found were in bus and lorry driving, construction, warehousing, agriculture and the banking and finance sector. Women in particular were likely to suffer, said Unite, which launched a “period dignity” campaign in September to highlight issues in workplaces.

It said problems experienced by many UK workers on a daily basis potentially had serious health risks and could exacerbate many conditions, but that employers were continuing to breach health, safety and welfare duties by not providing proper facilities.

Gail Cartmail, Unite’s assistant general secretary, said the examples were “simply staggering”, adding: “It is clearly deeply humiliating for the workers who are being denied toilet dignity. Employers have got absolutely no excuse for ensuring toilet dignity and if they fail to do so they should be prosecuted by the HSE (Health and Safety Executive).

“Unite will not be passive on this issue, if workers are denied toilet dignity we will name and shame the guilty parties.”

Unite’s research has been published to tie in with World Toilet Day on Monday 19 November. The organisers of the event say that 4.5 billion people across the world live without a safe toilet, and 1.8 billion use drinking water sources that may have been contaminated with faeces.