A cross-party group of MPs have written to Boris Johnson urging him to give “simply exhausted” unpaid carers a weekly break following the pressures of the coronavirus pandemic.

The group, led by the Liberal Democrat leader, Sir Ed Davey, is calling on the Prime Minister to provide emergency funding to local authorities in order to give every unpaid carer the support services needed to take a weekly break.

The letter sent by the group of 23 MPs, including politicians from the Labour Party and SNP, comes on the first day of Carers Week, a campaign aiming to raise awareness of the challenges unpaid carers face.

The signatories said that unpaid carers have “stepped up heroically” to look after elderly, disabled and vulnerable people since the start of the coronavirus crisis last March.

“They are doing a remarkable and important job in very difficult circumstances,” the letter said.

“But now most carers are simply exhausted. Most haven’t had a single break since the pandemic started.

“The brutal combination of lockdowns, shielding requirements and reduced support services have made the pandemic especially tough.”

Research published on Monday by Carers UK found that 72% of people caring unpaid for family or friends have not had any breaks from their caring role at all over the course of the pandemic.

A poll of 2,754 current carers and 96 former carers, carried out by the charity in April, found that carers lost, on average, 25 hours of support a month that they previously had from services or family and friends before the pandemic.

The MPs’ letter said: “It is essential that services such as day centres can reopen Covid-safe now, so that carers can finally take a break while the people they care for get the support they need.

“With local authority budgets so badly overstretched, the Government must provide immediate funding to make this possible – as part of a bigger emergency package to fill the funding gap in adult and children’s social care.”

Liberal Democrat leader Sir Ed added: “Unpaid carers have taken on dramatically increased caring responsibilities during Covid.

“Most haven’t been able to take a single break since the pandemic started. Most are simply exhausted.

“The Government must finally recognise the enormous contribution that unpaid carers make and give them the support they deserve.”