What is the law governing lateral transfers of solicitors to a law firm acting against their client?

In view of the fact that the outcome of this appeal hinges on the application of the principles governing lateral transfers of solicitors to a law firm acting against a client of the firm from which they had relocated, this judgment will now turn to the law governing that subject as enunciated in Martin v. Gray which, as already pointed out, is the definitive authority on that topic. The law governing lateral transfers

In Martin v. Gray, a junior member of a firm representing the appellant in an action, who had been privy to many confidences disclosed by the appellant to that firm’s senior partner, joined the firm representing the respondent. As in the case at bar, the appellant brought an application for an order removing the latter firm as solicitors of record for the respondent. The motions judge, while expressing satisfaction that the transferee had not passed on any of the confidential information to other members and that the likelihood of her doing so, either intentionally or unintentionally, was remote, nonetheless concluded the appearance of conflict or possible impropriety had to be avoided. Concluding that the continued participation of the impugned firm would constitute “a threat to the integrity of the trial and create the appearance of impropriety”, the motions judge allowed the application.