An employee can resign in response to a serious breach of contract by the employer and claim constructive unfair dismissal. The employee must not delay too long after the breach has occurred before resigning or s/he will be unsuccessful and will be taken to have ‘affirmed’ or waived the breach. Sometimes employees resign following a ‘last straw’ at the end of a course of conduct or series of breaches. The last straw does not have to be anything substantial.
What if the employee has affirmed a previous breach of contract, but then resigns in response to a last straw? Can that last straw revive the previous breach and allow the employee to bring a successful constructive dismissal claim? The Employment Appeal Tribunal has said that it cannot.
Ms MacKenzie was an assistant manager at Pets at Home. While pregnant she applied for a promotion. Pets at Home refused to fast-track her into the promoted role. She was not successful in an open recruitment process. While on maternity leave she applied again but was unsuccessful. A few months later a less experienced assistant manager told her he had been successful. Ms MacKenzie resigned and relied on his apparent promotion as the last straw. However, the EAT decided that Ms MacKenzie had a choice as to whether to resign at the time of the earlier breaches of contract (when she was not fast tracked for promotion) and chose not to. She had affirmed those breaches of contract and so she could not rely on them in her constructive dismissal claim.