Voting according to one's conscience is not imposing one's views on others. It is acting with integrity. No-one can be at peace who violates his own conscience. Politicians are no exception. I would expect every politician of whatever persuasion to vote according to his or her conscience on moral matters, and I believe that electors would expect nothing less from their candidates.
It has been a convention, in sensitive moral matters, that members of a political party have a conscience vote. Unfortunately that has not always been followed, causing extreme discomfort among party members and anguish for conscience.
In such a situation the matter of conscience becomes of crucial importance. No matter what the consequences there is no option but to follow one's conscience.
St Thomas More tried desperately to see if there were ways in which he could remain loyal to the king, even by saying nothing. Eventually he had to oppose the king on a matter of conscience and paid the ultimate price. His stand has made him revered around the world as a martyr.
The Vatican document asks for a conscience that is not only well-informed but formed by the teachings of the Church.
The pity of it is that, in many cases, one's faith has too little influence on one's decisions. The great privilege members of parliament have in framing and passing laws and implementing policies for a better society in which the rights and aspirations of all the community are protected and the common good is served should never be compromised by party pressure or popular sentiment if the issue is one of conscience.
The nobility of the call of politician demands the protection of life and promotion for policies that respect human dignity.