The United States Supreme Court has held that the mere presence of an undercover agent at a pretrial conference between a criminal defendant and his attorney does not violate the defendant's sixth amendment right to counsel or his fourteenth amendment right to a fair trial, and hence cannot be the basis of a section 1983 claim, absent proof that the agent revealed the substance of the consultation to the government.
Weatherford v. Bursey, 429 U.S. 545 (1977).
Nancy E. Pirt,
Constitutional Law - Sixth Amendment - Right to Counsel - Confidentiality of Attorney-Client Consultation,
Duq. L. Rev.
Available at: https://dsc.duq.edu/dlr/vol16/iss2/11