How to disqualify a solicitor?

In many non-disputed matters, one solicitor may act as common solicitor for all parties. But when the matter subsequently gets disputed, the same solicitor then seeks to represent one party in the dispute. If that happens, you may seek to disqualify the solicitor from acting for the other party. There are a few grounds to do so. Some common grounds are:

a. Solicitor is a potential witness;
b. Solicitor has received confidential information likely to prejudice your case;
c. Solicitor will be acting in conflict of interest.

But before you seek to disqualify any solicitor, think carefully. Would it be better to stick with the devil you know than the devil you don't?