What would you do if the client says that you and the other analysts cannot directly talk to the users?
If this happens then explain the purpose of your talk (e.g. capture requirements) and why its important to talk to users directly (e.g. the quality of requirements will be better if they comes directly from the users mouth). Explain them that it will be a high risk to the project if analyst can’t talk to the users directly. Client can give access to indirect (surrogate) users but explain that the quality of requirements will be not good. Hopefully your client will agree by now otherwise flag it as a higher risk in Business Requirement Document and highlight during your meeting with your PM and Project Sponsors. Now, it’s your PM or project sponsors duty to provide you access to those direct users. If they can’t than you are safe anyways.