The Roman Catholic Church in Scotland dealt a blow to the Labour Party when its bishops came out against Trident as churches urged their members to make use of their vote.

In a letter to all 500 Catholic churches in Scotland parishioners will be urged to vote as it says that "nuclear weapons represent a grave threat to the human family".

The Catholic Church's statement to be read this Sunday says: "The dignity and value of every human being should be at the heart of politics.

"The sanctity of human life, protected from its beginning to its natural end, is not a single issue.

"It is the fundamental issue."

It adds: "Politicians should defend the institution of marriage and the family as the basic unit of society on which so much depends."

"The first consideration for any economic policy should be the dignity of the person, not the pursuit of profit.

"Nuclear weapons represent a grave threat to the human family."

The letter will also say, that "on serious issues some politicians who profess a Catholic faith remain silent - or even surrender - in the face of grave ethical injustice".

The Moderator of the General Assembly of the Church of Scotland, Right Reverend John Chalmers, has written to all 1400 congregations saying the election offers "a real opportunity for the Church to share its vision for society".

Mr Chalmers said: 'There will be many issues important in this election and you will be the judge of what is important, and which party is best aligned with your view.

"Vote, if you are eligible, no matter which party you support.

"It is important to play your part in the democratic process.

"A government elected on a low turnout will have less moral authority than one where there has been strong participation."

In his letter to congregations, the moderator encourages members to attend local hustings meetings, or to arrange their own, either as congregation, Presbytery, Churches Together Group or local organisations