Legal ethics question

Hi,

I’m curious about legal ethics and whether there are any limits to what a legal firm can do to pursue a client’s interests.

It appears that honesty is not a requirement and, in issuing threatening correspondence, there is no need to verify that any allegation has any actual basis in fact.

However, I do have email trail that shows that the plaintiff in a child access case retained a court appointed psychologist in a private advisory capacity in advance of the preparation of an “independent” report and that their legal representative was closely involved. As a layman, this appears to be no different to interfering with or attempting to influence a witness and more than a little surprised that this seems to be considered acceptable.

Are there any laws or codes of conduct that would be contravened here?

It appears that the Law Society will only consider complaints from a client or another solicitor which, in itself, seems wrong. Surely wrongdoing is wrongdoing and investigation should be based on the merits of a complaint rather than who it making it?