British bosses must treat severely fat employees as disabled under European Union legislation on equal rights in the workplace, Europe's most senior legal advisor has warned.

UK companies will be required to treat obese workers as "disabled" providing them with larger seats, special parking spaces and other facilities.

The warning comes following a case brought to the EU courts by a Danish child minder, who claims he was sacked by his local authority employer in Denmark because he was so overweight.

Karsten Kaltoft, who is 25-stone, was fired amid reports that his weight meant he required help from a colleague to tie up a child's shoelaces.

The judgement is expected to follow along the lines of today's comments and rule in Kaltoft's favour.

Niilo Jaaskinen, the advocate general to the European Court of Justice said: "The origin of the disability is irrelevant" even if someone's obesity is caused by excessive eating.

"The notion of disability is objective and does not depend on whether the applicant has contributed causally to the acquisition of his disability through 'self-inflicted' excessive energy intake. Otherwise physical disability resulting from reckless risk-taking in traffic or sports would be excluded from the meaning of disability," he said.

An EU court ruling in Kaltoft's favour will be binding on British employers, who will have to bear the costs of finding ways to ensure fat workers are not placed at a disadvantage to slimmer colleagues.

"If obesity has reached such a degree that it plainly hinders participation in professional life, then this can be a disability," said the legal advice.