I have recently been assisting a union member in a disciplinary investigation. The whole disciplinary process was a shambles and the decision highly dubious; the outcome was the member was issued a final written warning for misconduct. Both the member and I were disappointed with the outcome and could not see how the finding had been reached from the evidence that was before the employer.
And yet, when it came to the question of whether to appeal a final written warning the member, as many other have before her, was reticent to appeal. One of the reasons was fear that the outcome of the appeal could be that the warning is uplifted to dismissal. In other words, on appeal the appeal manager will decide the earlier decision was too lax, and dismissal should have been the proper sanction.
The case of McMillan v Airedale NHS Foundation addresses that very issue. The claimant, a hospital consultant, was issued a final written warning for misconduct against which she appealed. The appeal panel indicated it would also consider sanction with the possibility the sanction could be increased. The claimant sought a High Court injunction before the employer had the chance to consider this which was granted; the employer appealed. The case was focused on the the specific contract of employment but did make clear that it will be rare that an employer has a specific right to increase the sanction on appeal.
Of more help to employees is the passing comments on the ACAS Code of Practice. The ACAS Code itself advises that a fair process requires that “Where an employee feels that disciplinary action taken against them is wrong or unjust they should appeal against the decision” (emphasis added). Although the Code does not clearly set out an increase in penalty is unreasonable the accompanying (and non statutory) ACAS Guide does set out that “An appeal must never be used as an opportunity to punish the employee for appealing the original decision, and it should not result in any increase in penalty as this may deter individuals from appealing.”
In McMillan it is precisely this language of appealing against a warning in that was instrumental in the Court of Appeal’s finding that a where there is a contractual disciplinary policy that allows an appeal against a warning the employer is contractually prohibited from increasing a sanction on appeal.
I think therefore that although not directly on point since McMillan is a employment contract case rather than an unfair dismissal one the decision gives a lot of confidence that an employer will find it next to impossible to justify increasing a sanction on appeal to dismissal unless there is an explicit contractual provision allowing it to do so.
McMillan v Airedale NHS Foundation  EWCA Civ 1031