Christians and other faith leaders have joined forces to oppose the Illegal Migration Bill currently making its way through Parliament.
The launch of the campaign coincides with Refugee Week and is being co-ordinated by Together With Refugees.
It has the support of the Bishop of Chelmsford, the Rt Rev Dr Guli Francis-Dehqani, who arrived in the UK at the age of 14 as a refugee from Iran.
She said, "This bill would allow the UK to turn its back on people in desperate need - denying safety to those who are vulnerable. Instead it would lock up people who have fled terrible circumstances in fear for their lives.
"I arrived in this country aged 14 and was given protection and welcome.
"But the proposals in this bill would mean detaining children who need help behind bars. I am proud to join with other faith leaders to stand with refugees against this bill. It does not represent who we are as faith leaders or as a nation."
The Illegal Migration Bill would block people arriving in small boats across the Channel from claiming asylum. It would also allow people, including children, to be detained for an unlimited period of time.
The proposals have been criticised by the UN, which said they "would amount to an asylum ban".
In a video voicing their joint opposition, leaders from the Muslim, Christian and Jewish faiths say the Illegal Migration Bill would "punish" people seeking sanctuary from war, persecution or oppression.
"As people of faith, we strive to welcome the stranger, to offer hospitality, to love, protect, listen, learn, and show compassion. This is who we are," they say.
"Across the UK, now and throughout history, individuals and communities of faith have welcomed refugees into their homes and lives. When people travel across borders because they are fleeing war, persecution or oppression, we are ready to play our part.
"But the Illegal Migration Bill will deny people desperately seeking safety in the UK the right to community, peace, compassion and security. It will ban people from getting the protection they need, punish them for seeking sanctuary, and separate families. Instead of hospitality, it treats people with hostility, discrimination and distrust.
"We believe in a different approach. We believe in a fair and just asylum system that welcomes those who need protection and respects their dignity. We call on the government to listen to communities who say this bill does not reflect what we want our country to be. As people of faith, we will stand together with refugees, because it's who we are."
Other Christians backing the campaign include the Bishop of Liverpool, the Rt Rev John Perumbalath, Emily Shepherd, Co-CEO of Welcome Churches, and Rev Sally Foster-Fulton, Moderator of the Church of Scotland General Assembly.
