9-20. Civil cases having several plaintiffs or several defendants; challenges apportioned; discretion of judge.
(a) When there are two or more defendants in a civil action, the presiding judge, if it appears that there are antagonistic interests between the defendants, may in the judge's discretion apportion among the defendants the challenges now allowed by law, or the judge may increase the number of challenges to not exceeding six for each defendant or class of defendants representing the same interest.
(b) When there are two or more plaintiffs in a civil action, the presiding judge, if it appears that there are antagonistic interests between the plaintiffs, may, in the judge's discretion, apportion among the plaintiffs the challenges now allowed by law, or the judge may increase the number of challenges to not exceeding six for each plaintiff or class of plaintiffs representing the same interest.
(c) Whenever a judge exercises the discretion authorized by subsection (a) or (b) of this section to increase the number of challenges for either the plaintiffs or the defendants, the judge may, in the judge's discretion, increase the number of challenges for the opposing side, not to exceed the total number given to the other side.