News that the Government is to face a fifth class action tax lawsuit – this time from a group of UK-based companies claiming hundreds of millions of pounds in rebates – is the latest sign that US-style litigation is becoming big business for those City firms with the requisite contentious tax capability.

While Group Litigation Orders (GLOs) were primarily introduced three years ago to handle negligence claims on behalf of groups of individuals, five out of the six GLOs to be granted this year involve corporate claimants.