Pet shops and dealers in England will be banned from selling puppies and kittens under government plans.

The proposals, which have gone out to consultation, will mean those wanting to buy or adopt a pet less than six months old will have to go to the breeder or a rescue centre.

A ban on licensed sellers dealing in dogs and cats less than eight weeks old is already coming in on 1 October.

Campaigners welcomed the announcement, but warned of "potential loopholes".

The ban aims to reduce the health problems associated which emerge when animals are reared in poor conditions.

It is a victory for the Lucy's Law campaign, which has been calling for the ban to be implemented.

The campaign was named after a Cavalier King Charles Spaniel who was badly treated in the puppy farming system.

A petition supporting Lucy's Law was signed by nearly 150,000 people and was debated in Parliament in May.

There are no records of the number of puppies sold via third parties, but the animal charity Blue Cross has estimated it is between 40,000 and 80,000 per year in Great Britain.

The Department for Environment, Food and rural Affairs said fewer than 100 third party sellers - which includes some pet shops - are licensed in England.

Speaking in support of a change, Environment Secretary Michael Gove said: "People who have a complete disregard for pet welfare will no longer be able to profit from this miserable trade."

The move was welcomed by Paula Boyden from the Dogs Trust - but she warned that "potential loopholes" needed to be closed off for the ban to be successful.

"We believe that to be effective, a ban needs to be supported by some key additional measures, such as regulating re-homing organisations," she said.

Sold online

The Mayhew Animal Home charity has previously highlighted the case of Luna, a Jack Russell terrier who was sold online despite being ill with a suspected skin disease.

At six weeks old, Luna was already under the legal age required for puppies to be sold - but the seller claimed the young dog was 10 weeks old.

In another case, the Dogs Trust said a French bulldog called Lola was forced to travel from eastern Europe so her puppies could be born and sold in the UK at a higher price. Two of her puppies later died.

Caroline Kisko, Kennel Club secretary, said the ban would "stop the suffering of many dogs and send a very strong message to puppy buyers that it is never OK to see a puppy in any environment other than the one it was born and raised in, and with its mum".

Marc Abraham, of the Pup Aid campaign, said: "Irresponsible breeders have for years used third parties to keep themselves hidden from the buying public and the proposed ban will make all breeders accountable."

Queen guitarist Brian May, who supports the Lucy's Law campaign, said it was "a day for celebration".

The Pet Industry Federation said puppy farms should be closed down but added there were concerns that an outright ban on third party sales would lead to sales "going underground".

Other rules already coming into force on 1 October include a requirement for any licensed pet seller to include their licence number in the advert as well as identifying the local authority that issued it and for breeders to show puppies alongside their mother before a sale is made.