Ucas admissions data from mid-December show applications from English students at their lowest since 2009.
The trebling of maximum tuition fees saw a drop in applications for autumn 2012 but university leaders hoped demand would recover in 2013.
A Ucas spokesman said it was too early to say whether overall applications would be down.
The general deadline for applying to start university in autumn 2013 is 15 January, although people may apply later.
These interim figures were collated by Ucas on 17 December, by which time some 265,730 people living in the UK had applied to start degree courses this autumn, down 6.3% on the same point in 2012.
Among students living in England, applications were down 6.5% on 2012 at 229,932.
The steepest drop in applications was from students living in Wales, down 11.7% to 11,218. Applications from Scottish students fell by 3.9% while there was a marginal increase in applications in Northern Ireland – up 0.5%.
|Applications by mid December||2009||2010||2011||2012||2013|
The Ucas spokesman stressed that the December sampling point was a few days before the end of term for many schools and suggested that many applications would have come in after that.
He pointed out that in previous years up to 40% of applications have come in during the final month before the deadline.
Pam Tatlow, chief executive of university group Million+ said: “The worrying trend of falling university applications continues, according to the most recent statistics published by UCAS.
“We urge the government to step in with a national campaign to promote the value of university for potential students currently considering their options, whether they are about to leave school or considering a university course later in life.”
But Dr Wendy Piatt, director general of the Russell Group of universities, agreed with UCAS that it was too early in the year to judge overall application figures.
“Let’s not jump the gun… It’s only right that prospective students are taking their time deciding which universities to apply to and making use of all the information available to them.”
Nicola Dandridge of Universities UK said the December figures were “a snapshot” but warned: “We must be concerned about any drops in the numbers applying to university and in particular, we must look closely at how the increase in graduate contributions in England may be affecting the decisions of prospective students.
“The December figures show a drop in numbers across the UK, suggesting that it is not solely a question of tuition fees in England putting students off from applying.”
University and College Union general secretary Sally Hunt said: “The bottom line is that hiking up the cost is likely to have an impact on people’s decisions when it comes to further study.
“We need our brightest people pursuing their dreams. We simply cannot afford to fall behind other countries that are seeing a rise in the number of students and graduates. More must be done to encourage people to aspire to university and far greater efforts made to support them when they are there.”
A government spokeswoman said: “It is too early to form a definitive picture about university applications for the 2013-14 academic year. Traditionally fewer than 50% of applicants have submitted their applications by this point in the cycle.
“It is important that no one is put off applying to university because they do not have information about the student support available to them. Most new students will not pay upfront, there will be more financial support for those from poorer families and everyone will make lower loan repayments than they do now once they are in well paid jobs.”
Applications to UK universities were at their highest in 2011 but dropped by 6.6% last year when the government increased tuition fees to up to £9,000 a year.