Britain's race equality watchdog has urged the leaders of Britain's political parties to reaffirm their commitment not to "stir up" racial hatred.
The Commission for Racial Equality made the request in response to a Liberal Democrat complaint that Labour and Conservative MPs were breaching a voluntary code on racial and religious tolerance.
The CRE's acting chairman Hugh Harris told Liberal Democrat home affairs spokesman Simon Hughes that he could not formally investigate his complaint because of the code's voluntary nature.
But in a two-page letter he told Mr Hughes: "Like you we agree that any debate involving the different racial backgrounds of people should be conducted in a responsible way, and without raising tensions between various ethnic groups.
"Like you, we are keen that all politicians stick to the terms of the CRE's Principles of Good Practice and Conduct that was signed in 1996, prior to the 1997 General Election, by the leaders of Britain's five main political parties.
"Like you, we would wish the leaders of all these parties to reaffirm their commitment."
Mr Harris said he was sending copies of the letter to Labour leader Tony Blair, Conservative leader William Hague, Liberal Democrat leader Charles Kennedy, the Scottish National Party's Alex Salmond and Plaid Cymru's Dafydd Wigley.
It asks them to:
Reject racial violence, harassment and violence.
Avoid election materials "which stir up or invite hostility or division between people of different racial or national groups, or which might reasonably be expected to stir up or invite such hostility of division".
Avoid using words or actions "which may" stir up racial hatred or lead to racial prejudice.
Ensure party workers are aware of the points.
Mr Harris said that the five party leaders had also signed another agreement in February last year following debate on the 1999 Immigration and Asylum Bill.
Both agreements were voluntary, and the CRE did not have any legal powers to take action on breaches of them, Mr Harris said.
But he pointed out that in the 1996 agreement the party leaders committed themselves to taking action against party members who breached the code.
He added: "It is therefore for the leaders of all parties to consider very carefully the language being used by themselves and their members on asylum seekers, immigration and race relations issues, and to take appropriate action to keep within the terms of the agreement."
Mr Harris avoided making any explicit criticism of the political parties.
However, he stressed that MPs "must not take a stance that increases tensions between the people, communities and cultures they represent".
And he said that while the organisation was not seeking to stifle free speech, there were people claiming asylum for "genuine reasons and who are in genuine risk of persecution and attack in their own country".
Mr Harris continued: "Any debate on the issue of asylum seekers should avoid stirring up resentment towards those who may be genuinely in need of help, and avoid impacting on race relations more generally."
Downing Street on Wednesday "reaffirmed" the Prime Minister's commitment to the all-party agreement, he said.
Mr Hughes, who made the complaint at the weekend, said he welcomed the CRE's "constructive approach".
"My intervention is absolutely not about trying to restrict freedom of speech," he said.
"But the nature and content of the debate was in danger of replacing fact with fiction and that the product was likely not to be a better informed public.
"Debate on sensitive issues should be conducted in a responsible and reasonable manner, particularly to avoid pandering to prejudice."Reuse content