Ministers have offered The Open University a "range of assurances" about the institution's future funding - but no specific guarantees of extra cash, it emerged this week.
Both the OU and Birkbeck College, University of London, have been lobbying ministers to offer more support to part-time students amid warnings that they have been "sidelined" by the government's higher education bill.
While the bill would abolish the upfront tuition fees and offer grants for full-time undergraduates from poor backgrounds - and extra income for universities by letting them charge full-time tuition fees of £3,000 a year - it would offer no such relief to part-time students.
OU chiefs told The Times Higher that they were still optimistic that the government would find an "interim solution" before the planned funding council review of university teaching finances after 2006.
David Vincent, pro vice-chancellor of the OU, said that ministers had given "a range of assurances" about future funding although nothing "tangible" had been received yet.
According to the latest figures, half of OU students are either unemployed or unskilled and half earn less than £25,000 a year.
The OU has argued that the introduction of tuition fees of up to £3,000 a year for full-time students from 2006 may widen the funding gap between part-time institutions and traditional universities.
Professor Vincent said: "The Open University is solvent at the moment, but our concern is the future.
"We will be facing a new economic situation from 2006 when we will be competing for research income and for staff against institutions that had benefited from a significant funding increase."
During the second reading of the higher education bill in the House of Lords last month, Baroness Boothroyd reminded the government that over the past 30 years "The Open University has by far made the greatest contribution to increasing access... so why have institutions such as The Open University not featured in this major item of legislation?"
It is understood that since the second reading of the bill in the Lords last month, both Baroness Boothroyd and OU vice-chancellor Brenda Gourley have had private meetings with ministers.
Although Professor Vincent declined to give details of the private meetings, he said: "We are grateful for comforting words, but we still have to balance our budget and we can't do so on words alone."
Professor Vincent added: "We are still hopeful that some interim solution can be found by the government."