UK students should be given the option to retake or be reimbursed for this academic year, says the National Union of Students.
The NUS is also calling for a student hardship fund to help those struggling.
The union says a survey of nearly 10,000 student union members shows 81% are worried about their future job prospects and 95% are concerned about the impact of Covid-19 on the economy.
The government says it understands this is a difficult time for students.
The survey was completed by 9,872 students across the UK, from all age ranges and learning experiences and reveals:
- 33% are at critical risk of being unable to access their education
- 74% are worried about the risk to their final qualifications
- 95% expressed fears about the impact of the virus on the wider economy
- 81% said they were concerned about their job prospects
- 71% worry about the impact the pandemic will have on their employability
- and up to 85% of working students may need additional financial support as incomes drop.
The NUS is urging the UK government to provide "comprehensive, urgent support" for students, saying a £60m national hardship fund should be made available to all students currently in further or higher education.
It calls for an economic package for those who complete their qualifications during the current pandemic, providing access to a grant which can be used for training, reskilling or development.
Earlier this month, the Scottish government announced a £5m package of emergency financial support to help students facing hardship because of the coronavirus outbreak.
The NUS also wants to see the option for "every student, in every part of education, to re-do this year at no further cost, with full maintenance support - while ensuring those returning to education next year receive high-quality education, training and support".
It calls for reimbursement of one year's course, college or tuition fees for students who have paid upfront, or a write-off of one year's debt for those who have paid through loans.
NUS National President Zamzam Ibrahim said UK students needed a "safety net" because the coronavirus outbreak had hit them financially and had affected the quality of their learning.
Ms Ibrahim said: "Face-to-face teaching and assessments have had to be hurriedly moved online, and placement and other practical activity has had to be cancelled.
"Students have lacked access to key resources, such as libraries and spaces, disabled students have been left unsupported, and students and staff have been struggling with other demands on their finances, welfare and wider lives as lockdown restrictions are enforced.
"The impact of this disruption will not be felt equally, with those on placements and disabled students feeling the impact particularly severely.
"Students are being forgotten during the Covid-19 pandemic. We are the future workforce that will have to help to rebuild our economy over the coming years.
"Students must not be forgotten," Ms Ibrahim said.
A Department for Education spokeswoman said: "We understand that this is a difficult time for students and we are working tirelessly with the sector to ensure students are supported and able to complete their studies.
"Students will continue to receive payments of maintenance loans for the remainder of the current academic year and where students are experiencing particular hardship, many universities will already have hardship funds to support students most in need.
"The Coronavirus Job Retention Scheme may also be available for those with a part-time employment contract."