The University of Reading is to close its physics department, this month's intake of 30 students being the last.
Reading's website promotes "golden opportunities" in physics
Reading said it regretted the decision, but the sort of investment that the department needed was not possible "in the current funding context".
The Institute of Physics said the way funding followed student numbers meant that universities were controlled by the choices of 17-year-olds.
It believes several other departments of physics could go within a few years.
Reading said its senior management board had proposed that its department of physics recruit no further students after the present year's intake, and should close by July 2010.
A final decision rests with the University Council in November.
Reading said it had 42 places on courses starting next month and had recruited 30 students from the UK and wider European Union.
Their courses would not be affected, it said.
"The university regrets having to make this recommendation.
"It follows an extensive process of review, which concluded that in order to maintain and build on our academic strength in the department of physics, we would need to invest in a way which is not feasible in the present climate.
"In the current funding context, Reading, like many institutions, has to direct its limited resources to academic areas of comparative strength."
The head of the department, Professor John Blackman, told BBC News he had taken one call from a "very unhappy" parent, and worried students had been coming to see him.
He had been able to assure them that their courses would be secure.
Prof Blackman's department has 33 academic and support staff
As to whether the closure decision would be confirmed, he said this might depend on the reaction to it.
"I have had a lot of messages of support from the science community, other universities and other people," Prof Blackman said.
Local MPs had asked to meet him.
"We wait to see whether the university feels that the whole thing is worth a rethink."
At the Institute of Physics, science director Peter Main said the great paradox was that physics graduates were very employable and well paid - but departments were at risk because of underfunding.
"There is a mismatch between what UK plc and employers want, and the economic drivers of universities."
This was almost at the "whim" of vice-chancellors, Prof Main said.
"Our members within the department in Reading are telling us that they were given assurances earlier in the year that there would not be a problem," he said.
It is understood the intention had been to recruit a professor and two lecturers and make certain economies.
But this plan had been suddenly dropped because, the university said, it had encountered unexpected expenses on utilities, buildings and this year's pay settlement.
Prof Main said: "We have lost Newcastle and now Reading. Two or three others, I would be very surprised if they lasted even another five years."
He declined to name those most at risk, but said that once they were lost it would be incredibly difficult to re-establish them.
"University vice-chancellors are operating in an environment that is controlled by the choices of 17-year-old students," Prof Main said.
"Funding follows student numbers and so the future of Britain's science base rests on the university choices of sixth-formers."
In fact undergraduate numbers have been holding up - but are not increasing in line with general demand.
The institute is one of the organisations that has been working with the Higher Education Funding Council for England (Hefce) on ideas to drive up demand. An announcement nationally is expected next week.
The funding council said it had been exploring with a group of six universities in the South East, including Reading, how to make physics more sustainable.