What is the current state of the law on solicitor’s duty of care in the context of a mortgage dispute?

As to the second issue, the law is found in Tracy v. Atkins, supra. There the court imposed the duty of care in circumstances where the solicitor placed himself in a "sufficient relationship of proximity resulting in a duty of care". See p. 227: Not in every case will a solicitor be in a relationship of such proximity with an opposing party as was the case here. In the circumstances of this case, the solicitor undertook to carry out all the conveyancing including work that would ordinarily be done by the vendor's solicitor, such as registration of the mortgage back. By undertaking to do so, he placed himself in the position of dealing with the plaintiffs' interests at a time when he knew or ought to have known that the plaintiffs were or might be relying on him to protect those interests. In the circumstances of this case, he placed himself in "a sufficient relationship of proximity" that he incurred a duty of care towards the plaintiffs....