The letter warns that the possibility of the UK leaving the EU without a deal in October has “dramatically increased” following Prime Minister Theresa May’s resignation.

It adds: “Failure to progress the current Withdrawal Agreement will mean the loss of even the limited safeguards to rights and other protections for Northern Ireland that were built into the backstop protocol.

“Civil society organisations are clear that the backstop protocol is the bare minimum that is required to protect the Northern Ireland economy, the rights of citizens and the Belfast/Good Friday Agreement.

“A no-deal Brexit means Northern Ireland will be thrown into a state of emergency and without a sitting executive to respond to this crisis, we face and unprecedented threat to our rights.”

The letter’s signatories include the Human Rights Consortium, the PILS Project, the Committee on the Administration of Justice (CAJ) and the Children’s Law Centre.

It has also been signed by the Northern Ireland Committee of the Irish Congress of Trade Unions; Northern Ireland Rural Women’s Network; Friends of the Earth Northern Ireland; Centre for Cross Border Studies; Northern Ireland Council for Voluntary Action; Women’s Resource and Development Agency; Northern Ireland Women’s European Platform; Focus: the Identity Trust; Northern Ireland Council for Racial Equality; Disability Action; and Unison NI.