My hon. Friend makes an important point that I will come on to. It is absolutely right that counsel or solicitor must not mislead the court, as officers of the court with a primary duty to the court and not to their client, but the disclosure of evidence is a different obligation on the defence. There is no corresponding legal duty on the defence to disclose information that is harmful to its case, because that is consistent with the fundamental principle that it is for the prosecution to prove its case and not for a defendant to prove their innocence.
As my right hon. Friend the Member for Chesham and Amersham rightly identified, there is an important duty on counsel and barristers; they have a professional code of conduct that includes the requirement to act ethically and with integrity at all times. That includes a prohibition on knowingly or recklessly misleading anyone, including a court, and a positive duty to behave in a way that maintains public trust and confidence in the proper administration of justice. My right hon. Friend mentioned that her constituent may have details of other cases where a court has been misled; I strongly encourage her to share those details with the CPS and the professional bodies responsible for barristers and solicitors.