Ways of giving religious groups a bigger say in government policies are being discussed by a special group of ministers.
Non-believers complain that church groups have too much influence
Various religious representatives are joining the ministerial working group, which is due to report by the end of the year.
The move follows a pledge from Tony Blair before the last election to give churches and groups representing all the major faiths better access to government.
It has prompted fears from some Labour MPs that faith-based groups could be given preferential treatment over secular organisations.
Home Office Minister Fiona Mactaggart is chairing the Steering Group Reviewing the Way Government Interfaces with Faith Communities, which began work earlier this summer.
Ms Mactaggart told BBC Radio 4's Today programme she was not convinced there needed to be a standing committee of religious leaders to be consulted on every policy.
But the government needed to consult at the earliest stage with faith groups, which were involved in delivering many public services.
"The reason why we believe we need to do it is that many people, in fact most people, in Britain identify themselves as a member for a faith group," said Ms Mactaggart.
"Therefore, it's important that we use the faith groups to reach people."
It was important also to identify the specific needs of particular faiths, she argued.
Some faiths, including many Muslims, felt excluded because of their religion rather than their race, she suggested.
Ms Mactaggart rejected claims that giving faith groups a bigger say in policy development amounted to discrimination against non-believers.
"To give a proper way of consulting with the organised faith communities does not exclude anyone else," added the minister.
Senior Labour MP Martin O'Neill is among those backbenchers worried about the ministerial group's work.
"What some of us would be concerned about is that by opening one door, you are necessarily closing others," he told Today.
Secular groups were doing similar work to faith-based organisations too, he stressed.
"It's quite correct that religious bodies should have an opportunity to have their voices heard," continued Mr O'Neill.
"But that must not be at the exclusion of what probably is the majority of the community, who do not sign up for the single issue religious groups' line on particular concerns."
Former CND chairman Bruce Kent, who describes himself as a retired priest, raised different concerns.
He said: "I have great fears that the government is once more trying to co-opt the churches to its agenda.
"I believe the churches are very far co-opted in all sorts of areas, from charity status to military chaplains to prison chaplains to all sorts of different consultation panels.
"I believe that the churches should be standing outside government and making their own position about justice and equality perfectly clear and it does not require further government co-operation to make that possible."
Keith Porteous Wood, executive chairman of the National Secular Society, complained Britain was mimicking the power the religious right were able to wield in America.
He said voters had elected Tony Blair the politician and did not want a theocracy.
Mr Porteous Wood told BBC News 24."There is an enormous amount out religious emphasis in the government and too much privilege for it.
"And here we are, another stage with minority religions getting another opportunity to influence policy at Number 10,"
In last year's census, more than seven out of 10 people described themselves as Christians.
In the survey, 23% of people either said they had no religion or did not state their religion.
The second most popular religion, according to the census, was Muslim (3%).