Equality watchdog chief Trevor Phillips has called for a new "highway code" to tackle the challenges of modern multi-ethnic Britain.
Trevor Phillips has said Britain is heading towards segregation
The "unspoken rules" of race relations needed updating, he told a fringe meeting of Muslims at the Conservative Party Conference.
This was, he said, because the UK was becoming more segregated socially, residentially and educationally.
But, he added, fragmentation by race and religion was alien to Britain.
"It is simply not in our nature," he told the Conservative Muslim Forum on the fringe in Blackpool.
Instead Britain was used to the idea of "one nation" and followed many "unspoken rules", which were equivalent to a highway code for its multi-ethnic society, he said.
But he warned that steps needed to be taken because all the evidence from the Commission for Racial Equality's own research was that despite many advances Britain still had "a great deal to do".
And in some respects Britain was heading "in the wrong direction", he added.
Challenging some assumptions of race relations doctrine, he questioned whether it was "really offensive to call someone coloured".
He also asked if judges were right to say school uniform was not compulsory for devout Muslims.
Did the practice of councils printing their important documents in a range of languages encourage separatism, he asked.
"We need to find ways of reaching a national agreement on some of these issues.
"We need to update our highway code of conduct to meet the needs of our multi-ethnic society."
Calling for a wide-ranging debate on this "code", he urged Muslims to take part on drawing up rules for creating a more integrated society.
If such an agreement was reached it would be the "greatest prize possible in a world riven with ethnic and religious strife", he said.
The call comes just weeks after the CRE chief sparked controversy by suggesting that Britain was "sleepwalking" into a nation of segregated communities.
His detailed critique of modern race relations urged a change in the way different cultures within the UK relate to each other.
Young people of different backgrounds should get together in music studios and sports clubs, for example.
And schools should "do all they can" to ensure their intake brings in boys and girls of all backgrounds, he added.