More than 100 charities have sent a letter to the home secretary, Shabana Mahmood, calling for an end to the “scapegoating of migrants”.

The letter, sent before her speech at the Labour party conference in Liverpool on Monday afternoon, was coordinated by Refugee Action and signed by 105 organisations from a wide range of sectors – including Save the Children, Mind, Oxfam, Shelter, Greenpeace and Friends of the Earth, as well as dozens of migrant and anti-racism charities. It has also been signed by the PCS union, which represents Border Force workers.

The signatories have called on Mahmood to find solutions to problems with housing, the climate crisis and the NHS, and end the use of “performative policies” that cause harm.

“The government wants to deliver growth and renew Britain. This requires tackling issues such as growing extreme inequality, underfunded councils, lack of investment in quality housing, a crumbling NHS, the climate emergency and polluted waters,” the letter says.

“Targeting refugees will do nothing to tackle these structural issues or improve people’s lives. It only serves as a dangerous smokescreen to scapegoat the most vulnerable and distract from the very real dangers to our society.”

It urges the home secretary to work with local authorities, charities and refugees, “who face the reality of the hostile policies and rhetoric”, to find solutions.

This summer, sometimes violent demonstrations outside hotels have intimidated people seeking asylum – as well as a large far-right-organised rally in London earlier this month, with estimates that between 110,000 and 150,000 attended.

“Anger and division will never satisfy voters in the long term. They cause tensions in our communities, dividing us and tearing the social fabric of our society,” the signatories warn.

“As the new home secretary, you now have an opportunity to turn the tide, and to end the scapegoating of migrants and performative policies that only cause harm.

“The government runs the risk of this country accelerating along a dangerous path, and now is the time to urgently correct this and change course.”

Tim Naor Hilton, the chief executive of Refugee Action, said: “Austerity and growing wealth inequality are among the real devils forcing more families to use food banks and creating longer waits to see a doctor or find a secure home.

“The breadth of support for this letter shows that blaming people seeking asylum for problems not created by them has huge consequences across all parts of society.”

Areeba Hamid, the co-executive director of Greenpeace UK, said: “A week after the new home secretary was appointed, more than 100,000 people joined a far-right rally in our capital, reprising scenes we thought were consigned to the dustbin of history. That should be a wake-up call.

“Like the home secretary, I am an example of the benefits immigration brings to the United Kingdom. Our companies, communities and cherished institutions like the NHS are filled with similar examples.

“If we are to stand for decency and inclusion, we need to start with changing the tone of our debate about immigration.”

A Home Office spokesperson said: “The home secretary has said that secure borders are an essential part of being a tolerant, open, generous country and she will explore all options to restore order to our immigration system.”