The appellant (T) appealed against a decision of the employment tribunal to dismiss her unfair dismissal claim against the respondent (S). T had been subject to a "relevant transfer" under the Transfer of Undertakings (Protection of Employment) Regulations 2006. Before the transfer, she had been employed in Camberwell by a primary care trust. As a result of the transfer, she was required to work for S in Beckenham. T, a single mother, objected to the move on the ground that it would increase the time spent on commuting. She resigned shortly after being required to move to the new location, asserting that there had been a fundamental breach of contract. Her initial contract of employment contained a clause stating that there might be occasions when she would be required to work "either temporarily or permanently at other locations within the Trust". The tribunal concluded that T's contract "should properly be interpreted so as to allow a transfer to locations which were operated by [S]"; that because S could only deploy staff at locations "which it itself owned or operated" the words "within the Trust" had to be treated as otiose; and that, as a result, on transfer "the benefit of the mobility clause transferred to [S] and to the locations which it owned". The tribunal also held that there had been no breach of reg.4(9) of the 2006 Regulations. It found that, although a change of location might well amount to a "substantial change in working conditions to [T's] material detriment", T's journey time to and from work had not become materially longer, so that, viewed objectively, there had been no material change to her detriment. T argued that the tribunal had (1) erred in its interpretation of the mobility clause in her contract of employment; (2) misdirected itself as to the proper interpretation of reg.4(9).

HELD: (1) The words "within the Trust" in the mobility clause could not be regarded as surplus or meaningless. They were plainly words of definition and restricted the relevant geographical area. Moreover, the contract fell to be construed at the time that it was entered into. S had sought to support the tribunal's conclusion by reference to the concept of "substantial equivalence" derived from French v MITIE Management Services Ltd (2002) ICR 1395 EAT. That concept applied where were practical difficulties in implementing a contractual term, but there were no such difficulties in this case, French considered. In the circumstances, T could not be required to move to Beckenham and S had breached her contract when it purported to require her to do so. (2) The two components to reg.4(9) which mattered for present purposes were firstly a "substantial change in working conditions" and secondly a change that was "to the material detriment" of the employee concerned. The tribunal appeared to have adopted the correct approach to the former. The phrase "working conditions" applied to contractual terms and conditions as well as to physical conditions, Merckx v Ford Motors Co Belgium SA (C-171/94) (1996) All ER (EC) 667 ECJ (6th Chamber) applied. Whether or not there had been a change in working conditions would be a simple question of fact. Whether or not it was a change of substance would also be a question of fact and the tribunal would need to consider the nature as well as the degree of the change in order to decide whether it was substantial. In the sense that the employee would not be the arbitrator of whether the change was substantial, it might be said that the approach was objective, but the character of the change was likely to be the most important aspect of determining whether it was substantial. As to the phrase "material detriment", the tribunal had erred in determining the matter as one that had to be objectively determined by weighing T's position against S's and deciding whose position was reasonable. The correct approach was to consider the employee's position and ask whether it was reasonable in the circumstances for him or her to adopt that position, Shamoon v Chief Constable of the Royal Ulster Constabulary (2003) UKHL 11, (2003) 2 All ER 26 applied.

Appeal allowed.