Chefs advise placing lobsters into boiling water while they are still alive as harmful bacteria in their flesh can rapidly multiply once they are dead.
The risk of food poisoning is reduced by cooking the lobster alive but Labour wants to outlaw the practice.
The proposals, which form part of a 50-point plan on protecting animals both in the UK and globally, were announced by Labour’s shadow environment secretary Sue Hayman.
Currently, lobster and squid are not included in the legal definition of an animal.— Labour Environment (@LabourDefra) August 28, 2019
Labour will recognise them as sentient animals, resulting in a ban on boiling lobsters alive.#AnimalWelfareManifesto pic.twitter.com/TtmwV5c5l1
Ms Hayman said Labour wanted to "bring Britain's animal welfare policy into the 21st century”.
Another proposal in the manifesto included a review into the use of whips by jockeys in horse racing.
The British Horseracing Authority has strict rules on the use of whipping, with jockeys limited to a maximum of seven times in a flat race or eight times in a jump race and the horse must be "in contention or clearly winning at the time" the force was applied.
Read more from Yahoo News UK:
Jockeys disobeying such rules face suspension.
But Ms Hayman confirmed that, under a future Labour government, the party would look to review whether the use of whips in horse racing should be further restricted.
Labour's animal welfare manifesto, as well as implementing the review into horse race whipping, includes plans to ban trophy hunting imports, outlaw keeping primates such as apes and monkeys as pets, and putting a stop to electric pulse fishing.
Other measures will include ensuring the maximum sentence can be handed out if a defendant is found guilty of animal cruelty against a wild animal, banning the sale and use of snares and glue traps, and working internationally to stop the return of commercial whaling.
Ms Hayman said: "Consulting with members and animal rights organisations means that our policies are not campaigns of the month like the Tories, but thought through and comprehensive measures that will bring Britain's animal welfare policy into the 21st century.
"This suite of policies on animal welfare seeks to build upon the longstanding leadership of the Labour Party on the issue of animal welfare.
"From bringing forward the landmark Hunting Act to protecting the treatment of domestic animals under the Animal Welfare Act, Labour has always placed the welfare of animals high on the policy agenda.
"Labour will ensure that we have a comprehensive legislative agenda in place to make sure that the UK has animal rights protections equal to or better than anywhere in the world.”
The party said the manifesto will also reiterate Labour's commitment to strengthening the Hunting Act, ending the badger cull, giving tenants the right to keep pets, enshrining animal sentience in law and ending the live export of animals for slaughter.
For rural communities, the manifesto will seek to guarantee and improve on animal welfare in farming as the UK prepares to leave the European Union, the party said.