Baroness Warsi risks starting a "culture war" with secularists because of her attack on "militant secularisation" ahead of her visit to the Vatican, critics have claimed.
Warsi, chairman of the Conservative Party and leader of a government delegation to the Vatican in Rome, voiced her "fear" in the Daily Telegraph.
"My fear is that a militant secularisation is taking hold of our societies," she wrote.
"We see it in any number of things: when signs of religion cannot be displayed or worn in government buildings; when states won't fund faith schools; and where religion is sidelined, marginalised and downgraded in the public sphere."
She calls for faith, particularly Christianity, to be put at the heart of British public life and likens secularism to totalitarianism.
"What she is saying is extremely dangerous and she could start a culture war with us," Terry Sanderson, president of the National Secular Society, told International Business Times UK.
"We are stuck now with a small bunch of pious politicians trying to force us into embracing a religion that we have, with our own conscience, rejected.
"Warsi is risking setting off a reaction against this Conservative Party that she will regret," he said.
"She might actually be damaging them by trying to force religion on to people who quite clearly do not want it.
"David Cameron is going to really rue this if he continues down this line. They will pay for that at the ballot box."
Warsi's audience with the pope is about "recognising the deep and intrinsic role of faith in Britain and overseas", said Warsi.
In a poll of 1,136 British Christians by the Richard Dawkins Foundation for Reason and Science 74 percent said they oppose religion having special influence on public policy.
"The Vatican is the last real absolute theocracy in the world and it is very difficult to know why we are, as a government, consulting them on internal policy," Sanderson said.
"What has it got to do with the pope what British policy is?"