Well to be accurate, all Christians have not just a right but a duty to tell you not to have an abortion.  We must seek every person's GREATEST good.    And a person's GREATEST good is not achieved by having an abortion.  Because an abortion is the taking of the life of a genetically complete human being, one with a totally unique and complete identity.

This complete identity "drives" all further development.  Identity precedes development.

All Christians have this duty.

In the same way that all Christians have a duty to stop people from killing themselves. 

The priest in this case is just reminding his flock (he wrote it in a pastoral column for his parish) of moral criteria. 

But there is no reason that any Christian should "build up walls" between them and the person contemplating abortion. 

Walls are bad, as Francis has pointed out.