Senior churchmen on Friday called on party leaders to keep the general election campaign clean.

The Archbishops of Canterbury and York have issued a joint open letter warning politicians not to engage in negative campaigning for the general election.

In the letter, entitled "That They May Have Life", Dr George Carey and Dr David Hope urge politicians to think about the long term. The letter says they must not lose sight of "Christian values".

They say it is easy for politicians at this time to think only of the short term but that wouldn't be in the interests of society.

The letter says: "Yet we all sense how tempting it can be, especially in an election season, for the short-term, the negative and the self-serving to dominate the political stage, for the political spotlight to focus less on what is in the long-term interests of us all than on what can inflict the maximum short-term damage on political opponents."

The church leaders continue: "Not only is that wrong from a Christian perspective, it does not serve the best interests of the society which we all share.''

Dr Carey and Dr Hope are careful to avoid any inference of party political motive.

"Categorically, we make no covert appeal to you to vote for one party or another. We should honour the call to public service and pray that God may guide all those who seek to represent us," they say.

However, the Archbishops point to "some of the areas of inquiry that may help us relate the cross of Christ to the ballot box".

Of great importance are candidates' own "personal attitudes and moral outlook, as well as the policies of the party to which they belong".

On the policies themselves, the letter reflects on some of the major issues in the general election.

The senior bishops stress rural concerns, saying we should consider "how to cross the deep divide between town and country?"

They ask: "How do they value marriage and the family for the communities we build and the offspring we nurture, or the schools and colleges in which those children learn? How do they address the task of caring responsibility for all of God's creation?"

The letter is being distributed throughout the Church of England for use in parishes from this weekend.

Charles Kennedy, the Lib Dem leader, said the archbishops "have got their pulpits and they should stick to that".