What IS an XL Bully? Government releases official definition amid warnings dog will be 'impossible to track' once ban comes into place because it is not a recognised breed

By A Mystery Man Writer

MailOnline looks at the key questions ahead of new rules coming into force on December 31 making it illegal to breed, sell, advertise, exchange, gift, rehome, abandon or allow XL Bully dogs to go stray.

Moment two 'XL bullies' run loose on street, jump at woman's car and try to attack another pet dog before police seize the animals

Mark Duell: All their latest coverage - Page 7

XL Bully D-day looms: MPs warn 'ambiguity' over breed will leave police even more stretched over Christmas and expert warns of 'disaster' - as videos show officers and owners struggling to handle

Dozens of XL Bully owners gather on seafront to walk their dogs unmuzzled for the last time before new restrictions come into force TODAY

XL Bully D-day looms: MPs warn 'ambiguity' over breed will leave police even more stretched over Christmas and expert warns of 'disaster' - as videos show officers and owners struggling to handle

Landowner offers XL Bully owners a 'lifeline' to walk their dogs without a lead or muzzles on private fields as ban comes into effect today

Mark Duell: All their latest coverage - Page 7

Dozens of XL Bully owners gather on seafront to walk their dogs unmuzzled for the last time before new restrictions come into force TODAY

XL Bully seized and two arrested after dog mauled a Chihuahua puppy to death in horror attack after escaping house

Dogs on death row: Illegal XL Bullys will be put down from TODAY and owners face jail if they don't comply with new law - but 70,000 dogs could still be unregistered

Dozens of XL Bully owners gather on seafront to walk their dogs unmuzzled for the last time before new restrictions come into force TODAY

Mark Duell: All their latest coverage - Page 7

Stay of execution for XL Bully puppies: Owners are given another six months to neuter dogs less than a year old - with minister hinting deadline could be pushed back even further