Horan urged the priests and their parishioners "to contact all candidates in your constituency and to challenge them on the issues raised in the Bishops' Conference of Scotland Pastoral letter on the General Election 2019."
Scottish constituencies make up 59 of the 650 seats in the House of Commons. While unaffiliated candidates can stand as independents, the vast majority of elected candidates are members of one of the main political parties.
The letter from the Scotland bishops also criticized pro-abortion rights advocacy backed by the U.K. government and the Scottish parliament.
"Our Governments should also promote a culture of life overseas, reversing the current practice of the U.K. government to support anti-life initiatives, which might be described as ideological colonization," the bishops said.
The bishops also highlighted rising homelessness and reliance on food banks. The government's two-child limit on tax credits disproportionately affects religious families, they said.
"Society relies on the building block of the family to exist," they said. "The love of man and woman in marriage and their openness to new life is the basic, fundamental cell upon which society is built."
Religious tolerance and religious freedom were also a focus. The bishops called for legislation that welcomes "all faiths and none," with respect for conscience rights and awareness of the need to work against religious persecution and intolerance around the world, including anti-Christian persecution.
"We believe that a creeping intolerance towards religious belief, including but not confined to Christianity, has become part of life in modern Britain," the bishops said. "Certain politicians and citizens are finding it increasingly difficult to be true to their faith in an environment that tries to restrict religion to the private sphere."
In line with recent comments by Pope Francis on his papal trip to Japan, the Scottish bishops also urged the next U.K. government to work to eliminate the U.K. nuclear arsenal and to move away from weapons industries which "fuel wars and instability across the world."
About ten percent of Scotland's 5.4 million people are Roman Catholic, while about 18% belong to the protestant Church of Scotland. Over half of Scottish people say they have no religion at all.