Sir, according to HMA, it is an offence of bigamy to marry another woman when the first marriage subsists. So, whtever may be the reason for marrying for second time, it should be followed by divorce to become valid. You must also note here that it is only the first wife who can file a case of bigamy against her husband and no body else can.
Even if the 1st wife gives consent, the 2nd marriage, for whatever reason is void. Because for a valid marriage u/HMA, no party can have a spouse living at the time of marriage. So, without divorcing the 1st wife the 2nd marriage have no legal validity. However, children born out of the 2nd marriage shall have right in the property of the father.