(a) The judgment of a court providing permanent alimony for the support of a spouse rendered on or after July 1, 1977, shall be subject to revision upon petition filed by either former spouse showing a change in the income and financial status of either former spouse. A petition shall be filed and returnable under the same rules of procedure applicable to divorce proceedings. No petition may be filed by either former spouse under this subsection within a period of two years from the date of the final order on a previous petition by the same former spouse. After hearing both parties and the evidence, the jury, or the judge where a jury is not demanded by either party, may modify and revise the previous judgment, in accordance with the changed income and financial status of either former spouse in the case of permanent alimony for the support of a former spouse, or in accordance with the changed income and financial status of either former spouse if such a change in the income and financial status is satisfactorily proved so as to warrant the modification and revision. In the hearing upon a petition filed as provided in this subsection, testimony may be given and evidence introduced relative to the income and financial status of either former spouse.

(b) Subsequent to a final judgment of divorce awarding periodic payment of alimony for the support of a spouse, the voluntary cohabitation of such former spouse with a third party in a meretricious relationship shall also be grounds to modify provisions made for periodic payments of permanent alimony for the support of the former spouse. As used in this subsection, the word "cohabitation" means dwelling together continuously and openly in a meretricious relationship with another person, regardless of the sex of the other person. In the event the petitioner does not prevail in the petition for modification on the ground set forth in this subsection, the petitioner shall be liable for reasonable attorney's fees incurred by the respondent for the defense of the action.

(c) When an action for revision of a judgment for permanent alimony under this Code section is pending, the court in its discretion may allow, upon motion, the temporary modification of such a judgment, pending the final trial on the petition. In considering an application for temporary modification under this subsection, the court shall consider evidence of any changed circumstances of the parties and the reasonable probability of the petitioner obtaining revision upon final trial. The order granting temporary modification shall be subject to revision by the court at any time before final trial.

(d) In proceedings for the modification of alimony for the support of a spouse pursuant to the provisions of this Code section, the court may award attorneys' fees, costs, and expenses of litigation to the prevailing party as the interests of justice may require.