Employees are only protected under the DDA if they can show that they are "disabled". This word has a specific legal meaning:

"a person has a disability ...if he has a physical or mental impairment which has a substantial and long-term effect on his ability to carry out normal day-to-day activities".

If a claimant does not satisfy this definition they are not protected under the DDA. This definition is further expanded upon in schedule 1 of the DDA where the meaning of the word "likely" is crucial:

• a person's impairment has a "long-term effect" if it is likely to last for at least 12 months;
• if an impairment ceases to affect a person's ability to carry out normal day-to-day activities it is to be treated as continuing to have that effect if it is likely to recur;
• if an impairment would be likely to have a substantial adverse effect, but for measures being taken to treat or correct it, it is to be treated as having that effect; and
• if a person has a progressive condition, a person shall be taken to have an impairment which has a substantial adverse effect if the condition is likely to result in such an impairment.

Previously, following official guidance issued by the Government, tribunals in England have interpreted the word "likely" to mean "more probable than not" i.e. having at least a 51% chance.

However, the Northern Irish Court of Appeal recently adopted an easier test, interpreting "likely" to mean "could well happen". The House of Lords was thus asked to adjudicate on the correct interpretation of the word "likely" in the case of SCA Packaging Limited v Boyle.

Comment
The House of Lords firmly rejected previous authority and agreed with the Irish Court of Appeal that, notwithstanding the official guidance, the meaning of "likely" in schedule 1of the DDA is "could well happen" and that the correct test was therefore less exacting for claimants than the more probable than not test.

Interestingly, the House of Lords also stressed that Government guidance on legislation cannot be regarded as an authority on statutory interpretation as this was the job of the courts alone. While such guidance may be helpful in illustrating practical issues it should not be relied upon by employers as a definitive statement of the meaning of the law.