The Intact Centre in Ingol has lost half of its workforce due to Covid isolation and says the remainder are struggling to cope.
Already the centre has been forced to close down its community food hub for a day because it could not staff it.
And bosses are warning other services are also at risk unless more volunteers come forward.
"This current Covid wave has stretched our resources beyond anything I've ever known," said Denise Hartley, the centre's chief executive officer.
"We help people in crisis. Our services make a difference to the lives of so many and we are determined to keep them running. But it is a real struggle."
Intact, which was launched in Whitby Avenue in 1993, is regarded as an essential lifeline for many local families and individuals in need of support.
In addition to its food pantry the charity offers advice services, counselling, employment support, an IT suite and has a cafe and a local nature reserve.
The majority of people who staff Intact are volunteers and without them the centre would not be able to function.
"It's been horrendous recently," said local councillor John Potter, who is a trustee of the charity and also the Lib-Dem leader on Preston City Council.
"We have areas in and around Ingol and Tanterton which are some of the most impoverished, not just in Preston but much further afield.
"This is a lifeline for them to get food, get help and advice and also to access services online. We need new volunteers to come forward and help us provide these services.
"Covid has impacted on everything that we do at Intact and we really must make sure that we stay open and accessible for the people who rely on us.
"Volunteering is a wonderful experience for many people and brings benefits of its own to those prepared to give their time and support to those who need it most."
Denise Hartley added: "People have been dropping like flies since Christmas with this Omicron variant of Covid.
"Unless we have a bank of volunteers to call upon it leaves all of our services vulnerable. Volunteers are essential for charities like us, otherwise we could have to close down some of those services.
"But it isn't just in the short-term. We need more volunteers in the long-term too. They are the life blood of our centre.
"At the moment we are trying to keep everything open with just a skeleton staff - half of our team are off isolating. Those who are here are stretched and we urgently need help to get through this.
"Now more than ever we need more people to sign up and help us deliver our vital services to some of the most vulnerable in the community.”
Centre staff say there are dozens of ways new volunteers can get involved. No previous experience is needed, full training is provided and there are lots of opportunities to gain invaluable
experience and new qualifications
The Intact Centre is open weekdays 9am to 4pm. Anyone interested, or who wants to know more, email the centre at: [email protected]
Want to see fewer ads? Subscribers to the Lancashire Post get access to the ad-lite version of our website, which features 70% fewer ads and faster load times for a better experience. Find out more