The European parliament has approved a suite of restrictions on the use of antibiotics on healthy farm animals in a bid to halt the spread of “superbugs” resistant to medical treatment.

Europe’s animals consume more antibiotics than humans on average, often via livestock feeds on factory farms, where farmers routinely use them as a prophylactic against the occurrence or spread of disease.

But with at least 25,000 people dying across Europe every year from antimicrobial-resistant infections, scientists have warned that without reform, routine medical interventions could soon become impossible.

The new legislation, which will become law by 2022, bans the use of human reserve antibiotics in veterinary medicine and the use of unprescribed animal antimicrobials.

Vets will have to provide data on volume and sales of antimicrobial medicines, and imported foods will need to meet EU standards, particularly on growth enhancement.

The Green MEP Molly Scott Cato said the package would ensure antibiotics remained “available and effective when we need them”.

“The restrictions on antibiotic use will also challenge the factory farming model where animal suffer appalling conditions and are packed together in unhealthy conditions,” she said. “Without the routine use of antibiotics, farmers will need to adopt better farming practices that will improve the life of farm animals across the EU. This is a major victory for public health and for animal welfare.”

Other measures in the package will proscribe the use of antibiotics for performance enhancement or to replace poor animal husbandry, and limit the drug treatment of whole groups of animals when only one is infected.

It is not clear whether all these new rules will be fully applied in the UK after Brexit.

A letter from the environment secretary, Michael Gove, to the Conservative MP Zac Goldsmith, seen by the Guardian, says: “There is a concern that such a restriction on the veterinary surgeon’s ability to prescribe antibiotics prophylactically for administration to groups of animals … could have a detrimental effect on the health and welfare of such livestock and exacerbate potential spread of disease.”

In parliament earlier this month, the farming minister George Eustice pledged to implement the EU’s antibiotic restrictions and said the government had “supported the EU’s main aims”.

But the letter makes clear that Gove “did voice concerns about the proposed restriction of prophylaxis to individual animals” in Brussels.

Cóilín Nunan of the Alliance to Save Our Antibiotics said that, taken with the government’s stated intent of keeping EU regulatory burdens in the sector to a minimum, “it suggests that post-Brexit the UK will be adopting light-touch regulation of farm antibiotics.

“The UK will then probably end up with some of the weakest regulatory standards in Europe, which raises questions about the kinds of trade deals we will be seeking with non-EU countries like the US, China and Australia, which have much higher levels of antibiotics in farming.

“It may in the end reverse the progress that has been made by British farmers in cutting their own antibiotic use.”