Four navy vessels will have the right to stop, check and impound all EU fishing boats operating within Britain's exclusive economic zone.
Four Royal Navy patrol ships will be ready from January 1 to help Britain protect its fishing waters in case of a no-deal Brexit, as Prime Minister Boris Johnson said the UK was likely to complete its EU exit in three weeks without a trade deal.
The Ministry of Defence "has conducted extensive planning and preparation to ensure that defence is ready for a range of scenarios at the end of the transition period", a spokesman said.
"This preparation includes a standby package of 14,000 personnel to ensure that we are ready to support other government departments and authorities over the winter period, including with the EU transition, Covid-19 and potential severe weather events," the spokesman said in an email to Reuters.
The 80-metre-long vessels will have the power to stop, check and impound all European Union fishing boats operating within Britain's exclusive economic zone (EEZ), which can extend 320 km from shore.
The Guardian newspaper reported earlier that two vessels will be deployed at sea with two on standby in case EU fishing boats enter the EEZ.
Britain quit the European Union in January but remains an informal member until December 31, the end of a transition period during which it has remained in the EU single market and customs union.
There are concerns about possible skirmishes between British and foreign fishing if no trade deal is reached, with existing transitional rules that give EU boats access to British waters set to expire at the end of the year.
A French minister said on Thursday that France would compensate its fishermen and take other measures to help them if talks for a post-Brexit trade deal collapse, in an effort to avoid skirmishes at sea between French and British boats.