Sole rights for agency introduction

[App23]

Sorry for the very long delay in replying I had no idea anyone had replied.
It was 6 months since first applying for a different role.

[sal]

Your best bet is to get Agency B (the one that you are currently working for) on the case, as they have something to lose from the Client Co sacking you.

If someone can change the ClientCo's mind, spooked by an agent, it's another agent.

if you have already built a relationship with the hiring manager you can point him the fact that the original "right to represent" e-mail is 6 months old and no longer valid, but that's a long shot.

[WTFH]

...which was never followed up nor came to anything...

Why didn't you follow it up? When you apply for a role, or get interviewed, you should make the effort to follow up on the applications and interviews. You're more likely to get a role if you do.

It was 6 months since first applying for a different role.

Your best bet is to get Agency B (the one that you are currently working for) on the case, as they have something to lose from the Client Co sacking you.

If someone can change the ClientCo's mind, spooked by an agent, it's another agent.

if you have already built a relationship with the hiring manager you can point him the fact that the original "right to represent" e-mail is 6 months old and no longer valid, but that's a long shot.

I agree with sal - get agent B to deal with it. As has been said before, your issue is not with the end client and you should not be looking at suing them. Your issue is with agent A. Agent B will probably want to fight this one, so get the two agents to sort it out.

...and the next time, you need to let an agent know that they are representing you only for a specific role, and that they have a specific timeframe to do the representation.