The simple answer is no.
In a case with both sides represented by Cloisters barristers, the President of the EAT (himself the ex-Head of Chambers) held that the test is exactly the same. The fundamental basis for an unfair dismissal claim lies in section 94. There is no reason for the automatic nature of the dismissal in s103A to modify the approach to territoriality.
Factually the claim was straightforward. The Tribunal had determined as a preliminary issue according to agreed facts that an Italian banker living and working in Singapore, under a contract governed by Singaporean law, could not bring a s103A Employment Rights Act 1996 whistleblowing claim in the Tribunal.
Chris Milsom and Jenn Danvers, acting for the Claimant sought to argue that Article 10 ECHR and Article 11 of the EU Charter of Fundamental Rights meant that protection should be granted. The EAT refused. Importantly they accepted the arguments of the Respondent, represented by Ed Williams and Catriona Stirling that Article 11 of the Charter cannot be greater than the territorial reach of Article 10 of the ECHR. The ECHR applies outside the territory of contracting states only in the context of specific state actions such as invasion or occupation.
The fact that the disclosure was made in the banking context which was a highly regulated field of great interest to the general public in the UK made no difference.
In any event, Parliament did not intend any broader territorial protection because they had inserted the protection provided by PIDA into the ERA which at the time was similarly circumscribed in terms of territoriality. Therefore it was clear that Parliament did not intend that those who made a disclosure, anywhere in the world, of any nature said to be of public interest should be protected against detriment or dismissal. Put simply, the test remained the same as all other unfair dismissal claims: whether there was a sufficiently close connection to the UK or UK employment law. In this case, there was not.