An employee for a large chain had been demoted to the role of team leader following disciplinary and signed a new contract for that role. However she maintained her objections to the role and after working in the new role for some 5 months eventually resigned (constructive dismissal).
The Employment Appeal Tribunal (EAT) has held that an employee’s written acceptance of new terms of employment for a demoted role did not affirm the contract of employment.
The legal principles in affirmation established in W E Cox Toner (International) Ltd v Crook  IRLR 443 were agreed (so we are seeing no new case law emerging: :
“13. … Mere delay by itself (unaccompanied by any express or implied affirmation of the contract) does not constitute affirmation of the contract; but if it is prolonged it may be evidence of an implied affirmation: Allen v Robles  1 WLR 1193. Affirmation of the contract can be implied. Thus, if the innocent party calls on the guilty party for further performance of the contract, he will normally be taken to have affirmed the contract since his conduct is only consistent with the continued existence of the contractual obligation. Moreover, if the innocent party himself does acts which are only consistent with the continued existence of the contract, such acts will normally show affirmation of the contract. However, if the innocent party further performs the contract to a limited extent but at the same time makes it clear that he is reserving his rights to accept the repudiation or is only continuing so as to allow the guilty party to remedy the breach, such further performance does not prejudice his right subsequently to accept the repudiation …”
The full case Novakovic v Tesco Stores Ltd EAT/0315/15 can be read: http://www.bailii.org/uk/cases/UKEAT/2016/0315_15_0103.html