The RSPCA has expressed serious welfare and ethical concerns following the introduction of a new bill which will shift the UK's policy on gene edited livestock.
The government announced new legislation through the Genetic Technology (Precision Breeding) Bill to allow rules around gene editing of crops - and eventually animals - to be relaxed in the UK.
The post-Brexit law change means that scientists will be able to undertake research and development using the technique, following years of restrictions due to EU law.
For the most part, farming industry groups, such as the NFU, welcomed the bill's introduction, calling it a 'science-based legislative change'.
The union said the legislation change had the potential to offer a number of benefits to UK food production and to the environment.
But the RSPCA has warned that "now is not the time to be relaxing the regulations" as the long-term consequences of using the technologies was not known.
The charity explained that there was "no history of safe and reliable use of gene editing in farm animals".
It warned that gene-editing had been "proven to cause unpredictable and unintended changes to the genetic makeup of animals", which could cause suffering.
And there were alternative approaches to achieving many of the proposed benefits of genetic technologies, for example, improving animal husbandry and reducing food waste, it said.
The charity's head of public affairs, David Bowles, said the introduction of the bill was 'incredibly disheartening and frustrating' from an animal welfare perspective.
He said there were "more ethical and humane ways" to solve issues in the farming industry "without pushing farm animals even further towards their physical limits".
"We understand that a regulatory framework will be set out around gene editing animals, but now is not the time to be relaxing the regulations," Mr Bowles said.
"The animal welfare impact of directly altering an animal’s genetic material can be unpredictable and we simply do not know the long-term consequences.
"There are potentially serious implications, for both farm animals and people who care about them and want to be ethical consumers."
Mr Bowles said the legislation change also called into question British exports of food to the EU, which at present has a strict ban on imports of gene edited food.
He added: “Leaving the EU has provided an opportunity to set the highest standards of welfare and we feel that allowing gene editing would be a serious step backwards which many people would not support."