Answer: It is an established halacha that if the wife refuses to live with her husband because she claims he is disgusting to her (ma'os alei) that it is impossible to force him to divorce her. This is explicitly stated by the Rema (E.H. 77:3). And even if it has been a number of years that they have separated and he is being spiteful and cruel in refusing to divorce her it is clearly stated by the Teshuvos haRosh (43:6) that if we force him to give the get there is the concern that it is a get me'usa and therefore invalid and it only serves to increase mamzerim. However while it is stated in the Rema (E.H. 154:21) that nidoi (cherem) is considered force and is prohibited, nevertheless he says it is permitted to decree that no Jew should do him a favor or should do business with him or even to circumcize his sons or to bury them - until he divorces his wife. But the Pischei Teshuva (E.H. 154:30) says there these shunnings (harhakos) are equivalent to nidoi (cherem) and are not permitted to be imposed today and the only recourse is to tell him that it is permitted to call him a sinner and he says it is best to be strict according to this opinion. This is agreed to by the Chazon Ish (E.H. 105:12). He concludes in the name of the Rashba that it is not permitted to humiliate the husband or to torment him - examine this well.
However it appears that what is prohibited is to humiliate him and to shun him in a manner similar to cherem - i.e, not to do business with him and not to do him a favor - and that is not done today. (Chazon Ish understands the Pischei Teshuva differently). But when he is not actively humiliated but that he is only not given honors for example he is notified that he will not receive an aliyah in his shul or any other shul and that he will not be allowed to be the shliach tzibor - then this is not like cherem at all even though it causes some humiliation. The only pressure permitted is that he should know that the community does not approve of his conduct of being cruel to his wife - but this is not called force at all.
